Method of treating mucopolysaccharidosis type I or II

ABSTRACT

Nucleases and methods of using these nucleases for inserting a sequence encoding a therapeutic protein such as an enzyme into a cell, thereby providing proteins or cell therapeutics for treatment and/or prevention of a lysosomal storage disease.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation-in-part of U.S. Ser. No.13/839,336, filed Mar. 15, 2013, which claims the benefit of U.S.Provisional Application No. 61/670,463, filed Jul. 11, 2012; U.S.Provisional Application No. 61/704,072, filed Sep. 21, 2012. Thisapplication also claims the benefit of U.S. Provisional Application No.62/058,400, filed Oct. 1, 2014, and U.S. Provisional Patent ApplicationNo. 62/089,070, filed Dec. 8, 2014, the disclosures of which are herebyincorporated by reference in their entireties.

SEQUENCE LISTING

The instant application contains a Sequence Listing which has beensubmitted electronically in ASCII format and is hereby incorporated byreference in its entirety. Said ASCII copy, created on Oct. 29, 2015, isnamed 8325009720_SL.txt and is 5,888 bytes in size.

TECHNICAL FIELD

The present disclosure is in the field of the treatment of Lysosomalstorage diseases (LSDs) and gene therapy.

BACKGROUND

Gene therapy holds enormous potential for a new era of humantherapeutics. These methodologies will allow treatment for conditionsthat heretofore have not been addressable by standard medical practice.One area that is especially promising is the ability to add a transgeneto a cell to cause that cell to express a product that previously notbeing produced in that cell. Examples of uses of this technology includethe insertion of a gene encoding a therapeutic protein, insertion of acoding sequence encoding a protein that is somehow lacking in the cellor in the individual and insertion of a sequence that encodes astructural nucleic acid such as a microRNA.

Transgenes can be delivered to a cell by a variety of ways, such thatthe transgene becomes integrated into the cell's own genome and ismaintained there. In recent years, a strategy for transgene integrationhas been developed that uses cleavage with site-specific nucleases fortargeted insertion into a chosen genomic locus (see, e.g., U.S. Pat. No.7,888,121). Nucleases, such as zinc finger nucleases (ZFNs),transcription activator-like effector nucleases (TALENs), or nucleasesystems such as the CRISPR/Cas system (utilizing an engineered guideRNA) or a TtAgo system, are specific for targeted genes and can beutilized such that the transgene construct is inserted by eitherhomology directed repair (HDR) or by end capture during non-homologousend joining (NHEJ) driven processes. See, e.g., U.S. Pat. Nos.9,045,763; 9,005,973; 8,956,828; 8,945,868; 8,932,814; 8,586,526;6,534,261; 6,599,692; 6,503,717; 6,689,558; 7,067,317; 7,262,054;7,888,121; 7,972,854; 7,914,796; 7,951,925; 8,110,379; 8,409,861; U.S.Patent Publications 20030232410; 20050208489; 20050026157; 20050064474;20060063231; 20080159996; 201000218264; 20120017290; 20110265198;20130137104; 20130122591; 20130177983; 20130177960; 20150056705 and20150335708, the disclosures of which are incorporated by reference intheir entireties.

Targeted loci include “safe harbor” loci such as the AAVS1, HPRT,albumin and CCR5 genes. See, e.g., U.S. Pat. Nos. 7,888,121; 7,972,854;7,914,796; 7,951,925; 8,110,379; 8,409,861; 8,586,526; U.S. PatentPublications 20030232410; 20050208489; 20050026157; 20060063231;20080159996; 201000218264; 20120017290; 20110265198; 20130137104;20130122591; 20130177983 and 20130177960. Nuclease-mediated integrationoffers the prospect of improved transgene expression, increased safetyand expressional durability, as compared to classic integrationapproaches that rely on random integration of the transgene, since itallows exact transgene positioning for a minimal risk of gene silencingor activation of nearby oncogenes.

While delivery of the transgene to the target cell is one hurdle thatmust be overcome to fully enact this technology, another issue that mustbe conquered is insuring that after the transgene is inserted into thecell and is expressed, the gene product so encoded must reach thenecessary location with the organism, and be made in sufficient localconcentrations to be efficacious. For diseases characterized by the lackof a protein or by the presence of an aberrant non-functional one,delivery of a transgene encoded wild type protein can be extremelyhelpful.

Lysosomal storage diseases (LSDs) are a group of rare metabolicmonogenic diseases characterized by the lack of functional individuallysosomal proteins normally involved in the breakdown of waste lipids,glycoproteins and mucopolysaccharides. These diseases are characterizedby a buildup of these compounds in the cell since it is unable toprocess them for recycling due to the mis-functioning of a specificenzyme. The most common examples are Gaucher's (glucocerebrosidasedeficiency—gene name: GBA), Fabry's (α galactosidase deficiency—GLA),Hunter's (iduronate-2-sulfatase deficiency—IDS), Hurler's (alpha-Liduronidase deficiency—IDUA), Pompe's (alpha-glucosidase (GAA)) andNiemann-Pick's (sphingomyelin phosphodiesterase 1 deficiency—SMPD1)diseases. When grouped all together, LSDs have an incidence in thepopulation of about 1 in 7000 births. These diseases have devastatingeffects on those afflicted with them. They are usually first diagnosedin babies who may have characteristic facial and body growth patternsand may have moderate to severe mental retardation. Treatment optionsinclude enzyme replacement therapy (ERT) where the missing enzyme isgiven to the patient, usually through intravenous injection in largedoses. Such treatment is only to treat the symptoms and is not curative,thus the patient must be given repeated dosing of these proteins for therest of their lives, and potentially may develop neutralizing antibodiesto the injected protein. Often these proteins have a short serum halflife, and so the patient must also endure frequent infusions of theprotein. For example, Gaucher's disease patients receiving the Cerezyme®product (imiglucerase) must have infusions three times per week.Production and purification of the enzymes is also problematic, and sothe treatments are very costly (>$100,000 per year per patient).

Nonetheless, there remains a need for additional methods andcompositions that can be used to treat a monogenic disease (e.g.Lysosomal storage diseases) through genome editing, and methods todeliver an expressed transgene encoded gene product at an increasedtherapeutically relevant level.

SUMMARY

Disclosed herein are methods and compositions for treating a monogenicdisease. The invention describes methods for insertion of a transgenesequence into an endogenous gene (e.g., albumin or HPRT) in a liver orstem cell, wherein the transgene encodes a protein that treats thedisease and the protein is expressed at increased levels (compared tountreated subjects) in the liver and active therapeutic protein isdetected in blood (plasma) and in secondary tissues such as spleen.Thus, the therapeutic protein is excreted from the target cell such thatit is able to affect or be taken up by other cells that do not harborthe transgene.

In one aspect, described herein is a method of providing a therapeuticprotein useful in treating a monogenic disease (e.g., LSD), the methodcomprising introducing the transgene into a cell (e.g., liver cell) intoan endogenous gene (e.g., a safe harbor gene such as albumin or HPRT) ina subject, such that the therapeutic protein is expressed in the liverand detectable in secondary tissues in the subject. The secondarytissues include blood (plasma), spleen, muscle, etc. Furthermore, theprotein may be expressed at increased levels in the liver and secondarytissues as compared to untreated subjects. In certain embodiments, theprotein is an enzyme and the methods result a 2-4 fold, or 2-10 fold or10-100 fold (or even more) increase in the enzymatic activity of theprotein in liver and/or secondary tissues. The transgene may beintegrated into the endogenous locus using a zinc finger nuclease, aTALEN, a CRISPR/Cas nuclease system and/or a Ttago nuclease system. Thenuclease may be introduced into the subject in polynucleotide form, forexample, as mRNA. In some aspects, the mRNA may be chemically modified(See e.g. Kormann et al, (2011) Nature Biotechnology 29(2):154-157). Insome aspects, mRNA is introduced via a nanoparticle, for example via aliposome or other type of nanoparticle. In some embodiments, thenuclease is introduced in a virus. In some aspects, the virus is an AAV.In certain embodiments, the transgenes is integrated into a safe harborlocus, for example, an albumin or HPRT locus. Targeted integration of atransgene into the HPRT locus can also result in inactivation of theendogenous HPRT, which in turn allows for selection of cells comprisingthe transgene.

In one aspect, the invention describes a method of treating a lysosomalstorage disease by inserting in a corrective transgene into a suitabletarget cell (e.g., liver cell) such that the product encoded by thatcorrective transgene is expressed. In one embodiment, the correctivetransgene is inserted into a cell line for the in vitro production ofthe replacement protein. The cells comprising the transgene or theprotein produced by the cells can be used to treat a patient in needthereof, for example following purification of the produced protein. Inanother embodiment, the corrective transgene is inserted into a targettissue in the body such that the replacement protein is produced invivo. In any of the methods described herein, the LSD may be Hurlerdisease and the transgene may encode iduronidase; or Hunter disease andthe transgene may be iduronate-2-sulfatase; and/or Gaucher disease andthe transgene may be glucocerebrosidase and/or Fabry disease and thetransgene may be α-galactosidase; and/or Pompe disease and the transgenemay be α-glucosidase. In some aspects, the expressed protein is excretedfrom the cell to act on or be taken up by other cells or target tissues(e.g. plasma, spleen, etc.) that lack the transgene. In some instances,the excreting cell is in the liver. In other instances, the targettissue is the brain. In other instances, the target is blood (e.g.,vasculature). In other instances, the target is skeletal muscle. In oneembodiment, the corrective gene comprises the wild type sequence of thefunctioning gene, while in other embodiments, the sequence of thecorrective transgene is altered in some manner to give enhancedbiological activity. In some aspects, the corrective transgene comprisesoptimized codons to increase biological activity, while in otheraspects, the sequence is altered to give the resultant protein moredesired function (e.g., improvement in stability, alteration of chargeto alter substrate binding etc.). In some embodiments, the transgene isaltered for reduced immunogenicity of the expressed protein. In othercases, the transgene is altered such that the encoded protein becomes asubstrate for transporter-mediated delivery in specific tissues such asthe brain (see Gabathuler et al. (2010) Neurobiology of Disease 37:48-57).

In some embodiments the transgene is expressed such that a therapeuticprotein product is retained within the cell (e.g., precursor or maturecell). In other embodiments, the transgene is fused to the extracellulardomain of a membrane protein such that upon expression, a transgenefusion will result in the surface localization of the therapeuticprotein. In some aspects, the extracellular domain is chosen from thoseproteins listed in Table 1. In some aspects, the edited cells alsocomprise a transmembrane protein to traffic the cells to a particulartissue type. In one aspect, the transmembrane protein is an antibody,while in others, the transmembrane protein is a receptor. In certainembodiments, the cell is a precursor (e.g., CD34+ or hematopoietic stemcell) or mature RBC. In some aspects, the therapeutic protein productencoded on the transgene is exported out of the cell through use of asecretory peptide linked to the therapeutic protein to affect or betaken up by cells lacking the transgene. In some aspects, the secretorypeptide is heterologous to the therapeutic protein and is removed duringthe secretion process. In further aspects, the secretory peptide is anendogenous albumin secretory peptide. In certain embodiments, the cellis a liver cell which releases the therapeutic protein into the bloodstream to act on distal tissues (e.g., brain).

In one embodiment, the transgene is expressed from the endogenouspromoter following insertion into the endogenous locus (e.g., theendogenous albumin promoter following insertion into the endogenousalbumin gene or the endogenous HPRT promoter following insertion intothe endogenous HPRT gene). The biologic encoded by the transgene thenmay be released into the blood stream if the transgene is inserted intoa hepatocyte in vivo. In some aspects, the transgene is delivered to theliver in vivo in a viral vector through intravenous injection.

In another embodiment, the transgene encodes a non-coding RNA, e.g. anshRNA. Expression of the transgene prior to cell maturation will resultin a cell containing the non-coding RNA of interest.

In one aspect, described herein is a genetically modified cell or cellline, for example as compared to the wild-type genomic sequence of thesame type of cell or cell line (e.g., stem cell). The cell or cell linemay be heterozygous or homozygous for the modification. Themodifications may comprise insertions, deletions and/or combinationsthereof and in certain embodiments are in an HPRT gene. In certainembodiments, the cells are modified with an engineered nuclease and adonor nucleic acid such that a wild type gene (e.g., protein lacking ina lysosomal storage disease) is inserted and expressed and/or anendogenous aberrant gene is corrected. In certain embodiments, themodification (e.g., insertion) is at or near the nuclease(s) bindingand/or cleavage site(s), including but not limited to, modifications tosequences within 1-300 (or any number of base pairs therebetween) basepairs upstream or downstream of the site(s) of cleavage and/or bindingsite; modifications within 1-100 base pairs (or any number of base pairstherebetween) of either side of the binding and/or cleavage site(s);modifications within 1 to 50 base pairs (or any number of base pairstherebetween) on either side of the binding and/or cleavage site(s);and/or modifications to one or more base pairs of the nuclease bindingsite and/or cleavage site. In certain embodiments, the modification isat or near (e.g., 1-300 base pairs or any number of base pairstherebetween) SEQ ID NO:24 or 25. In other embodiments, the modificationis 1-100 (or any number of base pairs therebetween) base pairs of SEQ IDNO:24 or 25. In certain embodiments, the modification is within SEQ IDNO:24 and/or SEQ ID NO:25, for example a modification of 1 or more basepairs in either SEQ ID NO:24 or 25. Partially or fully differentiatedcells descended from the genetically modified stem cells as describedherein are also provided (e.g., RBCs or RBC precursor cells).Compositions such as pharmaceutical compositions comprising thegenetically modified cells as described herein are also provided. Thus,the methods of the invention may be used in vivo in transgenic animalsystems. In some aspects, the transgenic animal may used in modeldevelopment where the transgene encodes a human gene. In some instances,the transgenic animal may be knocked out at the corresponding endogenouslocus, allowing the development of an in vivo system where the humanprotein may be studied in isolation. Such transgenic models may be usedfor screening purposes to identify small molecules, or largebiomolecules or other entities which may interact with or modify thehuman protein of interest. In some aspects, the transgene is integratedinto the selected locus (e.g., albumin, HPRT, or other safe-harborlocus) into a stem cell (e.g., an embryonic stem cell, an inducedpluripotent stem cell, a hepatic stem cell, a neural stem cell etc.) oranimal embryo obtained by any of the methods described herein, and thenthe embryo is implanted such that a live animal is born. The animal isthen raised to sexual maturity and allowed to produce offspring whereinat least some of the offspring comprise the integrated transgene.

A kit, comprising the ZFN, TALEN, and/or CRISPR/Cas or TtAgo system ofthe invention, is also provided. The kit may comprise nucleic acidsencoding the ZFN, TALEN, and/or CRISPR/Cas or TtAgo system, (e.g. RNAmolecules or the ZFN, TALEN, and/or CRISPR/Cas or TtAgo system encodinggenes contained in a suitable expression vector), donor molecules,expression vectors encoding the single guide RNA suitable host celllines, instructions for performing the methods of the invention, and thelike.

These and other aspects will be readily apparent to the skilled artisanin light of disclosure as a whole.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a table showing the experimental design and viral constructsused for integration of the indicated Hurler, Hunter and Gaucher donorsusing into wild-type mice using albumin-targeted nucleases (ZFNs).

FIG. 2 depicts Western blot results of iduronidase expression in livercells of the indicated animals (controls (“Ctrl”), donor+ZFNs, donoronly and ZFN only). The material in each lane is derived from a singlemouse liver biopsy on the day indicated (D7, D21, D28). The numbers forthe groups (1, 2, 3, and 9) indicate the groups as shown in FIG. 1. Aloading control “GAPDH” is shown at the bottom of the figure.

FIGS. 3A to 3D are graphs depicting iduronidase activity in plasma inthe indicated animals as measured by enzymatic activity assay. Enzymeactivity is shown for control animals (“formulation”), animals receivingZFN and the iduronidase-encoding donor (“ZFN+donor”) andiduronidase-encoding only donor only (“donor only”) at day 7 (FIG. 3A),day 14 (FIG. 3B), day 21 (FIG. 3C) and day 28 (FIG. 3D).

FIG. 4 depicts Western blot results of iduronate-2-sulfatase expressionin liver cells of the indicated animals (controls, donor+ZFNs, donoronly and ZFN only), labeled as described for FIG. 2. A loading control(“GADPH”) is shown at the bottom of the figure.

FIGS. 5A to 5D are graphs depicting iduronate-2-sulfatase activity inplasma in the indicated animals as measured by enzymatic activity assay.Enzyme activity is shown for control animals (“formulation”), animalsreceiving ZFN and the iduronate-2-sulfatase-encoding donor (“ZFN+donor”)and iduronate-2-sulfatase-encoding only donor only (“donor only”) at day7 (FIG. 5A), day 14 (FIG. 5B), day 21 (FIG. 5C) and day 28 (FIG. 5D).

FIGS. 6A to 6E are graphs depicting glucocerebrosidase/GBA1 activity inplasma in the indicated animals as measured by enzymatic activity assay.Enzyme activity is shown for control animals (“formulation”), animalsreceiving ZFN and the glucocerebrosidase-encoding donor with or withoutimmune suppression (“IS”) (“ZFN+donor no IS” and “ZFN+donor w/IS”), andanimals receiving and glucocerebrosidase-encoding only donor only(“donor only”) at day 7 (FIG. 6A), day 14 (FIG. 6B), day 21 (FIG. 6C),day 28 (FIG. 6D) and day 42 (FIG. 6E).

FIG. 7 is an illustration of the iduronate sulfatase (IDS) cDNAtransgene donor and its integration into the endogenous HPRT locus. Thedonor construct is shown across the top and comprises AAV6 LTR sequences(“AAV”), the right and left homology arms, homologous to the endogenousHPRT gene, that flank the IDS transgene (“R-HA” for right homology armand “L-HA” for left homology arm), a splice acceptor site (“SA”), a 2Aself-cleaving peptide sequence (“2A”), and the IDS cDNA transgene (“IDScDNA”). The middle line shows the endogenous HPRT for integration of thedonor transgene, and bottom line shows an illustration of the integratedIDS cDNA transgene into the endogenous HPRT gene.

FIGS. 8A to 8D show graphs displaying the results of IDS transgeneinsertion into K562 cells. FIG. 8A shows the viability of the cellsfollowing transfection, with and without 6-TG selection while FIG. 8Bshows the percent of NHEJ observed in these cell populations. FIG. 8Cshows the percent of alleles in the cell population comprising an IDStransgene with and without 6-TG selection while FIG. 8D depicts the IDSenzymatic activity measured in the cell supernatant.

FIGS. 9A to 9D show graphs displaying the results of IDS transgeneinsertion into mobilized human CD34+ cells. FIG. 9A shows the viabilityof the cells following transfection, with and without 6-TG selectionwhile FIG. 9B shows the percent of NHEJ observed in these cellpopulations. FIG. 9C shows the percent of alleles in the cell populationcomprising a IDS transgene with and without 6-TG selection while FIG. 9Ddepicts the IDS enzymatic activity measured in the cell supernatant.

FIGS. 10A to 10C show graphs of IDUA activity in MPS1 mice treated withalbumin ZFNs (AAV) and AAV-IDUA transgene donor. FIG. 10A shows IDUApresent in the liver, FIG. 10B shows IDUA in the plasma and FIG. 10Cshows IDUA detected in the spleen, kidney and lung.

FIGS. 11A to 11C shows graphs of IDS activity in MPSII mice treated withalbumin ZFNs (AAV) and AAV-IDS transgene donor. FIG. 11A shows the IDSpresent in the liver, FIG. 11B shows the IDS in the plasma and FIG. 11Cshows the IDS present in the spleen, kidney and lung.

FIGS. 12A and 12B are graphs of GAG levels found in the urine and in thetissues of MPSI mice treated as in FIG. 10. Treatment of mice with ZFNand IDUA donor was associated with lower GAG levels that untreated mice.

FIGS. 13A and 13B are graphs of GAG levels found in the urine and in thetissues of MPSII mice treated as in FIG. 11. Treatment of mice with ZFNand IDS donor was associated with lower GAG levels that untreated mice.

DETAILED DESCRIPTION

Disclosed herein are methods and compositions for treating or preventinga lysosomal storage disease (LSD). The invention provides methods andcompositions for insertion of a gene encoding a protein that is lackingor insufficiently expressed in the subject with the LSD such that thegene introduced into an endogenous (e.g., albumin or HPRT) gene suchthat the gene is expressed and the therapeutic (replacement) protein isexpressed in the liver of the subject and in secondary tissues such asplasma, spleen, etc. at significantly increased levels (4 to 100 fold ormore) as compared to untreated subjects. The transgene encodes a protein(e.g., enzyme) that is deficient of lacking in an LSD.

General

Practice of the methods, as well as preparation and use of thecompositions disclosed herein employ, unless otherwise indicated,conventional techniques in molecular biology, biochemistry, chromatinstructure and analysis, computational chemistry, cell culture,recombinant DNA and related fields as are within the skill of the art.These techniques are fully explained in the literature. See, forexample, Sambrook et al. MOLECULAR CLONING: A LABORATORY MANUAL, Secondedition, Cold Spring Harbor Laboratory Press, 1989 and Third edition,2001; Ausubel et al., CURRENT PROTOCOLS IN MOLECULAR BIOLOGY, John Wiley& Sons, New York, 1987 and periodic updates; the series METHODS INENZYMOLOGY, Academic Press, San Diego; Wolffe, CHROMATIN STRUCTURE ANDFUNCTION, Third edition, Academic Press, San Diego, 1998; METHODS INENZYMOLOGY, Vol. 304, “Chromatin” (P. M. Wassarman and A. P. Wolffe,eds.), Academic Press, San Diego, 1999; and METHODS IN MOLECULARBIOLOGY, Vol. 119, “Chromatin Protocols” (P. B. Becker, ed.) HumanaPress, Totowa, 1999.

Definitions

The terms “nucleic acid,” “polynucleotide,” and “oligonucleotide” areused interchangeably and refer to a deoxyribonucleotide orribonucleotide polymer, in linear or circular conformation, and ineither single- or double-stranded form. For the purposes of the presentdisclosure, these terms are not to be construed as limiting with respectto the length of a polymer. The terms can encompass known analogues ofnatural nucleotides, as well as nucleotides that are modified in thebase, sugar and/or phosphate moieties (e.g., phosphorothioatebackbones). In general, an analogue of a particular nucleotide has thesame base-pairing specificity; i.e., an analogue of A will base-pairwith T.

The terms “polypeptide,” “peptide” and “protein” are usedinterchangeably to refer to a polymer of amino acid residues. The termalso applies to amino acid polymers in which one or more amino acids arechemical analogues or modified derivatives of a correspondingnaturally-occurring amino acids.

“Binding” refers to a sequence-specific, non-covalent interactionbetween macromolecules (e.g., between a protein and a nucleic acid). Notall components of a binding interaction need be sequence-specific (e.g.,contacts with phosphate residues in a DNA backbone), as long as theinteraction as a whole is sequence-specific. Such interactions aregenerally characterized by a dissociation constant (K_(d)) of 10⁻⁶ M⁻¹or lower. “Affinity” refers to the strength of binding: increasedbinding affinity being correlated with a lower K_(d).

A “binding protein” is a protein that is able to bind to anothermolecule. A binding protein can bind to, for example, a DNA molecule (aDNA-binding protein), an RNA molecule (an RNA-binding protein) and/or aprotein molecule (a protein-binding protein). In the case of aprotein-binding protein, it can bind to itself (to form homodimers,homotrimers, etc.) and/or it can bind to one or more molecules of adifferent protein or proteins. A binding protein can have more than onetype of binding activity. For example, zinc finger proteins haveDNA-binding, RNA-binding and protein-binding activity.

A “zinc finger DNA binding protein” (or binding domain) is a protein, ora domain within a larger protein, that binds DNA in a sequence-specificmanner through one or more zinc fingers, which are regions of amino acidsequence within the binding domain whose structure is stabilized throughcoordination of a zinc ion. The term zinc finger DNA binding protein isoften abbreviated as zinc finger protein or ZFP.

A “TALE DNA binding domain” or “TALE” is a polypeptide comprising one ormore TALE repeat domains/units. The repeat domains are involved inbinding of the TALE to its cognate target DNA sequence. A single “repeatunit” (also referred to as a “repeat”) is typically 33-35 amino acids inlength and exhibits at least some sequence homology with other TALErepeat sequences within a naturally occurring TALE protein. See; e.g.,U.S. Pat. No. 8,586,526.

Zinc finger and TALE binding domains can be “engineered” to bind to apredetermined nucleotide sequence, for example via engineering (alteringone or more amino acids) of the recognition helix region of a naturallyoccurring zinc finger or TALE protein. Therefore, engineered DNA bindingproteins (zinc fingers or TALEs) are proteins that are non-naturallyoccurring. Non-limiting examples of methods for engineering DNA-bindingproteins are design and selection. A designed DNA binding protein is aprotein not occurring in nature whose design/composition resultsprincipally from rational criteria. Rational criteria for design includeapplication of substitution rules and computerized algorithms forprocessing information in a database storing information of existing ZFPand/or TALE designs and binding data. See, for example, U.S. Pat. Nos.8,568,526; 6,140,081; 6,453,242; and 6,534,261; see also WO 98/53058; WO98/53059; WO 98/53060; WO 02/016536 and WO 03/016496.

A “selected” zinc finger protein or TALE is a protein not found innature whose production results primarily from an empirical process suchas phage display, interaction trap or hybrid selection. See e.g., U.S.Pat. Nos. 8,586,526; 5,789,538; 5,925,523; 6,007,988; 6,013,453;6,200,759; WO 95/19431; WO 96/06166; WO 98/53057; WO 98/54311; WO00/27878; WO 01/60970 WO 01/88197, WO 02/099084.

“TtAgo” is a prokaryotic Argonaute protein thought to be involved ingene silencing. TtAgo is derived from the bacteria Thermus thermophilus.See, e.g., Swarts et al, ibid, G. Sheng et al., (2013) Proc. Natl. Acad.Sci. U.S.A. 111, 652). A “TtAgo system” is all the components requiredincluding, for example, guide DNAs for cleavage by a TtAgo enzyme.

“Recombination” refers to a process of exchange of genetic informationbetween two polynucleotides, including but not limited to, donor captureby non-homologous end joining (NHEJ) and homologous recombination. Forthe purposes of this disclosure, “homologous recombination (HR)” refersto the specialized form of such exchange that takes place, for example,during repair of double-strand breaks in cells via homology-directedrepair mechanisms. This process requires nucleotide sequence homology,uses a “donor” molecule to template repair of a “target” molecule (i.e.,the one that experienced the double-strand break), and is variouslyknown as “non-crossover gene conversion” or “short tract geneconversion,” because it leads to the transfer of genetic informationfrom the donor to the target. Without wishing to be bound by anyparticular theory, such transfer can involve mismatch correction ofheteroduplex DNA that forms between the broken target and the donor,and/or “synthesis-dependent strand annealing,” in which the donor isused to resynthesize genetic information that will become part of thetarget, and/or related processes. Such specialized HR often results inan alteration of the sequence of the target molecule such that part orall of the sequence of the donor polynucleotide is incorporated into thetarget polynucleotide.

In the methods of the disclosure, one or more targeted nucleases asdescribed herein create a double-stranded break in the target sequence(e.g., cellular chromatin) at a predetermined site, and a “donor”polynucleotide, having homology to the nucleotide sequence in the regionof the break, can be introduced into the cell. The presence of thedouble-stranded break has been shown to facilitate integration of thedonor sequence. The donor sequence may be physically integrated or,alternatively, the donor polynucleotide is used as a template for repairof the break via homologous recombination, resulting in the introductionof all or part of the nucleotide sequence as in the donor into thecellular chromatin. Thus, a first sequence in cellular chromatin can bealtered and, in certain embodiments, can be converted into a sequencepresent in a donor polynucleotide. Thus, the use of the terms “replace”or “replacement” can be understood to represent replacement of onenucleotide sequence by another, (i.e., replacement of a sequence in theinformational sense), and does not necessarily require physical orchemical replacement of one polynucleotide by another.

In any of the methods described herein, additional pairs of zinc-fingerproteins or TALEN can be used for additional double-stranded cleavage ofadditional target sites within the cell.

Any of the methods described herein can be used for insertion of a donorof any size and/or partial or complete inactivation of one or moretarget sequences in a cell by targeted integration of donor sequencethat disrupts expression of the gene(s) of interest. Cell lines withpartially or completely inactivated genes are also provided.

Furthermore, the methods of targeted integration as described herein canalso be used to integrate one or more exogenous sequences. The exogenousnucleic acid sequence can comprise, for example, one or more genes orcDNA molecules, or any type of coding or noncoding sequence, as well asone or more control elements (e.g., promoters). In addition, theexogenous nucleic acid sequence may produce one or more RNA molecules(e.g., small hairpin RNAs (shRNAs), inhibitory RNAs (RNAis), microRNAs(miRNAs), etc.).

In certain embodiments of methods for targeted recombination and/orreplacement and/or alteration of a sequence in a region of interest incellular chromatin, a chromosomal sequence is altered by homologousrecombination with an exogenous “donor” nucleotide sequence. Suchhomologous recombination is stimulated by the presence of adouble-stranded break in cellular chromatin, if sequences homologous tothe region of the break are present.

In any of the methods described herein, the exogenous nucleotidesequence (the “donor sequence” or “transgene”) can contain sequencesthat are homologous, but not identical, to genomic sequences in theregion of interest, thereby stimulating homologous recombination toinsert a non-identical sequence in the region of interest. Thus, incertain embodiments, portions of the donor sequence that are homologousto sequences in the region of interest exhibit between about 80 to 99%(or any integer therebetween) sequence identity to the genomic sequencethat is replaced. In other embodiments, the homology between the donorand genomic sequence is higher than 99%, for example if only 1nucleotide differs as between donor and genomic sequences of over 100contiguous base pairs. In certain cases, a non-homologous portion of thedonor sequence can contain sequences not present in the region ofinterest, such that new sequences are introduced into the region ofinterest. In these instances, the non-homologous sequence is generallyflanked by sequences of 50-1,000 base pairs (or any integral valuetherebetween) or any number of base pairs greater than 1,000, that arehomologous or identical to sequences in the region of interest. In otherembodiments, the donor sequence is non-homologous to the first sequence,and is inserted into the genome by non-homologous recombinationmechanisms.

“Cleavage” refers to the breakage of the covalent backbone of a DNAmolecule. Cleavage can be initiated by a variety of methods including,but not limited to, enzymatic or chemical hydrolysis of a phosphodiesterbond. Both single-stranded cleavage and double-stranded cleavage arepossible, and double-stranded cleavage can occur as a result of twodistinct single-stranded cleavage events. DNA cleavage can result in theproduction of either blunt ends or staggered ends. In certainembodiments, fusion polypeptides are used for targeted double-strandedDNA cleavage.

A “cleavage half-domain” is a polypeptide sequence which, in conjunctionwith a second polypeptide (either identical or different) forms acomplex having cleavage activity (preferably double-strand cleavageactivity). The terms “first and second cleavage half-domains;” “+ and −cleavage half-domains” and “right and left cleavage half-domains” areused interchangeably to refer to pairs of cleavage half-domains thatdimerize.

An “engineered cleavage half-domain” is a cleavage half-domain that hasbeen modified so as to form obligate heterodimers with another cleavagehalf-domain (e.g., another engineered cleavage half-domain). U.S. Pat.Nos. 7,888,121; 7,914,796; 8,034,598 and 8,823,618, incorporated hereinby reference in their entireties.

The term “sequence” refers to a nucleotide sequence of any length, whichcan be DNA or RNA; can be linear, circular or branched and can be eithersingle-stranded or double stranded. The term “donor sequence” refers toa nucleotide sequence that is inserted into a genome. A donor sequencecan be of any length, for example between 2 and 100,000,000 nucleotidesin length (or any integer value therebetween or thereabove), preferablybetween about 100 and 100,000 nucleotides in length (or any integertherebetween), more preferably between about 2000 and 20,000 nucleotidesin length (or any value therebetween) and even more preferable, betweenabout 5 and 15 kb (or any value therebetween).

A “homologous, non-identical sequence” refers to a first sequence whichshares a degree of sequence identity with a second sequence, but whosesequence is not identical to that of the second sequence. For example, apolynucleotide comprising the wild-type sequence of a mutant gene ishomologous and non-identical to the sequence of the mutant gene. Incertain embodiments, the degree of homology between the two sequences issufficient to allow homologous recombination therebetween, utilizingnormal cellular mechanisms. Two homologous non-identical sequences canbe any length and their degree of non-homology can be as small as asingle nucleotide (e.g., for correction of a genomic point mutation bytargeted homologous recombination) or as large as 10 or more kilobases(e.g., for insertion of a gene at a predetermined ectopic site in achromosome). Two polynucleotides comprising the homologous non-identicalsequences need not be the same length. For example, an exogenouspolynucleotide (i.e., donor polynucleotide) of between 20 and 10,000nucleotides or nucleotide pairs can be used.

Techniques for determining nucleic acid and amino acid sequence identityare known in the art. Typically, such techniques include determining thenucleotide sequence of the mRNA for a gene and/or determining the aminoacid sequence encoded thereby, and comparing these sequences to a secondnucleotide or amino acid sequence. Genomic sequences can also bedetermined and compared in this fashion. In general, identity refers toan exact nucleotide-to-nucleotide or amino acid-to-amino acidcorrespondence of two polynucleotides or polypeptide sequences,respectively. Two or more sequences (polynucleotide or amino acid) canbe compared by determining their percent identity using standardtechniques. Typically the percent identities between sequences are atleast 70-75%, preferably 80-82%, more preferably 85-90%, even morepreferably 92%, still more preferably 95%, and most preferably 98%sequence identity.

Alternatively, the degree of sequence similarity between polynucleotidescan be determined by hybridization of polynucleotides under conditionsthat allow formation of stable duplexes between homologous regions,followed by digestion with single-stranded-specific nuclease(s), andsize determination of the digested fragments. Two nucleic acid, or twopolypeptide sequences are substantially homologous to each other whenthe sequences exhibit at least about 70%-75%, preferably 80%-82%, morepreferably 85%-90%, even more preferably 92%, still more preferably 95%,and most preferably 98% sequence identity over a defined length of themolecules, as determined using the methods known in the art. Conditionsfor hybridization are well-known to those of skill in the art.Hybridization stringency refers to the degree to which hybridizationconditions disfavor the formation of hybrids containing mismatchednucleotides, with higher stringency correlated with a lower tolerancefor mismatched hybrids. Factors that affect the stringency ofhybridization are well-known to those of skill in the art and include,but are not limited to, temperature, pH, ionic strength, andconcentration of organic solvents such as, for example, formamide anddimethylsulfoxide. As is known to those of skill in the art,hybridization stringency is increased by higher temperatures, lowerionic strength and lower solvent concentrations.

“Chromatin” is the nucleoprotein structure comprising the cellulargenome. Cellular chromatin comprises nucleic acid, primarily DNA, andprotein, including histones and non-histone chromosomal proteins. Themajority of eukaryotic cellular chromatin exists in the form ofnucleosomes, wherein a nucleosome core comprises approximately 150 basepairs of DNA associated with an octamer comprising two each of histonesH2A, H2B, H3 and H4; and linker DNA (of variable length depending on theorganism) extends between nucleosome cores. A molecule of histone H1 isgenerally associated with the linker DNA. For the purposes of thepresent disclosure, the term “chromatin” is meant to encompass all typesof cellular nucleoprotein, both prokaryotic and eukaryotic. Cellularchromatin includes both chromosomal and episomal chromatin.

A “chromosome,” is a chromatin complex comprising all or a portion ofthe genome of a cell. The genome of a cell is often characterized by itskaryotype, which is the collection of all the chromosomes that comprisethe genome of the cell. The genome of a cell can comprise one or morechromosomes.

An “episome” is a replicating nucleic acid, nucleoprotein complex orother structure comprising a nucleic acid that is not part of thechromosomal karyotype of a cell. Examples of episomes include plasmidsand certain viral genomes.

An “accessible region” is a site in cellular chromatin in which a targetsite present in the nucleic acid can be bound by an exogenous moleculewhich recognizes the target site. Without wishing to be bound by anyparticular theory, it is believed that an accessible region is one thatis not packaged into a nucleosomal structure. The distinct structure ofan accessible region can often be detected by its sensitivity tochemical and enzymatic probes, for example, nucleases.

A “target site” or “target sequence” is a nucleic acid sequence thatdefines a portion of a nucleic acid to which a binding molecule willbind, provided sufficient conditions for binding exist.

An “exogenous” molecule is a molecule that is not normally present in acell, but can be introduced into a cell by one or more genetic,biochemical or other methods. “Normal presence in the cell” isdetermined with respect to the particular developmental stage andenvironmental conditions of the cell. Thus, for example, a molecule thatis present only during embryonic development of muscle is an exogenousmolecule with respect to an adult muscle cell. Similarly, a moleculeinduced by heat shock is an exogenous molecule with respect to anon-heat-shocked cell. An exogenous molecule can comprise, for example,a functioning version of a malfunctioning endogenous molecule or amalfunctioning version of a normally-functioning endogenous molecule.

An exogenous molecule can be, among other things, a small molecule, suchas is generated by a combinatorial chemistry process, or a macromoleculesuch as a protein, nucleic acid, carbohydrate, lipid, glycoprotein,lipoprotein, polysaccharide, any modified derivative of the abovemolecules, or any complex comprising one or more of the above molecules.Nucleic acids include DNA and RNA, can be single- or double-stranded;can be linear, branched or circular; and can be of any length. Nucleicacids include those capable of forming duplexes, as well astriplex-forming nucleic acids. See, for example, U.S. Pat. Nos.5,176,996 and 5,422,251. Proteins include, but are not limited to,DNA-binding proteins, transcription factors, chromatin remodelingfactors, methylated DNA binding proteins, polymerases, methylases,demethylases, acetylases, deacetylases, kinases, phosphatases,integrases, recombinases, ligases, topoisomerases, gyrases andhelicases.

An exogenous molecule can be the same type of molecule as an endogenousmolecule, e.g., an exogenous protein or nucleic acid. For example, anexogenous nucleic acid can comprise an infecting viral genome, a plasmidor episome introduced into a cell, or a chromosome that is not normallypresent in the cell. Methods for the introduction of exogenous moleculesinto cells are known to those of skill in the art and include, but arenot limited to, lipid-mediated transfer (i.e., liposomes, includingneutral and cationic lipids), electroporation, direct injection, cellfusion, particle bombardment, calcium phosphate co-precipitation,DEAE-dextran-mediated transfer and viral vector-mediated transfer. Anexogeneous molecule can also be the same type of molecule as anendogenous molecule but derived from a different species than the cellis derived from. For example, a human nucleic acid sequence may beintroduced into a cell line originally derived from a mouse or hamster.

By contrast, an “endogenous” molecule is one that is normally present ina particular cell at a particular developmental stage under particularenvironmental conditions. For example, an endogenous nucleic acid cancomprise a chromosome, the genome of a mitochondrion, or otherorganelle, or a naturally-occurring episomal nucleic acid. Additionalendogenous molecules can include proteins, for example, transcriptionfactors and enzymes.

As used herein, the term “product of an exogenous nucleic acid” includesboth polynucleotide and polypeptide products, for example, transcriptionproducts (polynucleotides such as RNA) and translation products(polypeptides).

A “fusion” molecule is a molecule in which two or more subunit moleculesare linked, preferably covalently. The subunit molecules can be the samechemical type of molecule, or can be different chemical types ofmolecules. Examples of the first type of fusion molecule include, butare not limited to, fusion proteins (for example, a fusion between a ZFPor TALE DNA-binding domain and one or more activation domains) andfusion nucleic acids (for example, a nucleic acid encoding the fusionprotein described supra). Examples of the second type of fusion moleculeinclude, but are not limited to, a fusion between a triplex-formingnucleic acid and a polypeptide, and a fusion between a minor groovebinder and a nucleic acid.

Expression of a fusion protein in a cell can result from delivery of thefusion protein to the cell or by delivery of a polynucleotide encodingthe fusion protein to a cell, wherein the polynucleotide is transcribed,and the transcript is translated, to generate the fusion protein.Trans-splicing, polypeptide cleavage and polypeptide ligation can alsobe involved in expression of a protein in a cell. Methods forpolynucleotide and polypeptide delivery to cells are presented elsewherein this disclosure.

A “gene,” for the purposes of the present disclosure, includes a DNAregion encoding a gene product (see infra), as well as all DNA regionswhich regulate the production of the gene product, whether or not suchregulatory sequences are adjacent to coding and/or transcribedsequences. Accordingly, a gene includes, but is not necessarily limitedto, promoter sequences, terminators, translational regulatory sequencessuch as ribosome binding sites and internal ribosome entry sites,enhancers, silencers, insulators, boundary elements, replicationorigins, matrix attachment sites and locus control regions.

“Gene expression” refers to the conversion of the information, containedin a gene, into a gene product. A gene product can be the directtranscriptional product of a gene (e.g., mRNA, tRNA, rRNA, miRNA,antisense RNA, ribozyme, structural RNA or any other type of RNA) or aprotein produced by translation of an mRNA. Gene products also includeRNAs which are modified, by processes such as capping, polyadenylation,methylation, and editing, and proteins modified by, for example,methylation, acetylation, phosphorylation, ubiquitination,ADP-ribosylation, myristilation, and glycosylation.

“Modulation” of gene expression refers to a change in the activity of agene. Modulation of expression can include, but is not limited to, geneactivation and gene repression. Genome editing (e.g., cleavage,alteration, inactivation, activation, random mutation) can be used tomodulate expression. Gene inactivation refers to any reduction in geneexpression as compared to a cell has not been modified as describedherein (e.g., by a ZFP, TALE and/or CRISPR/Cas system). Geneinactivation may be partial or complete.

A “region of interest” is any region of cellular chromatin, such as, forexample, a gene or a non-coding sequence within or adjacent to a gene,in which it is desirable to bind an exogenous molecule. Binding can befor the purposes of targeted DNA cleavage and/or targeted recombination.A region of interest can be present in a chromosome, an episome, anorganellar genome (e.g., mitochondrial, chloroplast), or an infectingviral genome, for example. A region of interest can be within the codingregion of a gene, within transcribed non-coding regions such as, forexample, leader sequences, trailer sequences or introns, or withinnon-transcribed regions, either upstream or downstream of the codingregion. A region of interest can be as small as a single nucleotide pairor up to 2,000 nucleotide pairs in length, or any integral value ofnucleotide pairs.

“Eukaryotic” cells include, but are not limited to, fungal cells (suchas yeast), plant cells, animal cells, mammalian cells and human cells(e.g., T-cells).

“Secretory tissues” are those tissues in an animal that secrete productsout of the individual cell into a lumen of some type which are typicallyderived from epithelium. Examples of secretory tissues that arelocalized to the gastrointestinal tract include the cells that line thegut, the pancreas, and the gallbladder. Other secretory tissues includethe liver, tissues associated with the eye and mucous membranes such assalivary glands, mammary glands, the prostate gland, the pituitary glandand other members of the endocrine system. Additionally, secretorytissues include individual cells of a tissue type which are capable ofsecretion.

The terms “operative linkage” and “operatively linked” (or “operablylinked”) are used interchangeably with reference to a juxtaposition oftwo or more components (such as sequence elements), in which thecomponents are arranged such that both components function normally andallow the possibility that at least one of the components can mediate afunction that is exerted upon at least one of the other components. Byway of illustration, a transcriptional regulatory sequence, such as apromoter, is operatively linked to a coding sequence if thetranscriptional regulatory sequence controls the level of transcriptionof the coding sequence in response to the presence or absence of one ormore transcriptional regulatory factors. A transcriptional regulatorysequence is generally operatively linked in cis with a coding sequence,but need not be directly adjacent to it. For example, an enhancer is atranscriptional regulatory sequence that is operatively linked to acoding sequence, even though they are not contiguous.

With respect to fusion polypeptides, the term “operatively linked” canrefer to the fact that each of the components performs the same functionin linkage to the other component as it would if it were not so linked.For example, with respect to a fusion polypeptide in which a ZFP, TALEor Cas DNA-binding domain is fused to an activation domain, the ZFP,TALE or Cas DNA-binding domain and the activation domain are inoperative linkage if, in the fusion polypeptide, the ZFP, TALE of CasDNA-binding domain portion is able to bind its target site and/or itsbinding site, while the activation domain is able to upregulate geneexpression. When a fusion polypeptide in which a ZFP, TALE or CasDNA-binding domain is fused to a cleavage domain, the ZFP, TALE orCasDNA-binding domain and the cleavage domain are in operative linkageif, in the fusion polypeptide, the ZFP, TALE or Cas DNA-binding domainportion is able to bind its target site and/or its binding site, whilethe cleavage domain is able to cleave DNA in the vicinity of the targetsite (e.g., 1 to 500 base pairs or any value therebetween on either sideof the target site).

A “functional fragment” of a protein, polypeptide or nucleic acid is aprotein, polypeptide or nucleic acid whose sequence is not identical tothe full-length protein, polypeptide or nucleic acid, yet retains thesame function as the full-length protein, polypeptide or nucleic acid. Afunctional fragment can possess more, fewer, or the same number ofresidues as the corresponding native molecule, and/or can contain one ormore amino acid or nucleotide substitutions. Methods for determining thefunction of a nucleic acid (e.g., coding function, ability to hybridizeto another nucleic acid) are well-known in the art. Similarly, methodsfor determining protein function are well-known. For example, theDNA-binding function of a polypeptide can be determined, for example, byfilter-binding, electrophoretic mobility-shift, or immunoprecipitationassays. DNA cleavage can be assayed by gel electrophoresis. See Ausubelet al., supra. The ability of a protein to interact with another proteincan be determined, for example, by co-immunoprecipitation, two-hybridassays or complementation, both genetic and biochemical. See, forexample, Fields et al. (1989) Nature 340:245-246; U.S. Pat. No.5,585,245 and PCT WO 98/44350.

A “vector” is capable of transferring gene sequences to target cells.Typically, “vector construct,” “expression vector,” and “gene transfervector,” mean any nucleic acid construct capable of directing theexpression of a gene of interest and which can transfer gene sequencesto target cells. Thus, the term includes cloning, and expressionvehicles, as well as integrating vectors.

A “reporter gene” or “reporter sequence” refers to any sequence thatproduces a protein product that is easily measured, preferably althoughnot necessarily in a routine assay. Suitable reporter genes include, butare not limited to, sequences encoding proteins that mediate antibioticresistance (e.g., ampicillin resistance, neomycin resistance, G418resistance, puromycin resistance), sequences encoding colored orfluorescent or luminescent proteins (e.g., green fluorescent protein,enhanced green fluorescent protein, red fluorescent protein,luciferase), and proteins which mediate enhanced cell growth and/or geneamplification (e.g., dihydrofolate reductase). Epitope tags include, forexample, one or more copies of FLAG, His, myc, Tap, HA or any detectableamino acid sequence. “Expression tags” include sequences that encodereporters that may be operably linked to a desired gene sequence inorder to monitor expression of the gene of interest.

A “safe harbor” locus is a locus within the genome wherein a gene may beinserted without any deleterious effects on the host cell. Mostbeneficial is a safe harbor locus in which expression of the insertedgene sequence is not perturbed by any read-through expression fromneighboring genes. Non-limiting examples of safe harbor loci inmammalian cells are the AAVS1, HPRT, albumin and CCR5 genes in humancells, and Rosa26 in murine cells (see, e.g., U.S. Pat. Nos. 7,888,121;7,972,854; 7,914,796; 7,951,925; 8,110,379; 8,409,861; 8,586,526; U.S.Patent Publications 20030232410; 20050208489; 20050026157; 20060063231;20080159996; 201000218264; 20120017290; 20110265198; 20130137104;20130122591; 20130177983 and 20130177960) and the Zp15 locus in plants(see U.S. Pat. No. 8,329,986).

The terms “subject” and “patient” are used interchangeably and refer tomammals such as human patients and non-human primates, as well asexperimental animals such as rabbits, dogs, cats, rats, mice, and otheranimals. Accordingly, the term “subject” or “patient” as used hereinmeans any mammalian patient or subject to which the or stem cells of theinvention can be administered. Subjects of the present invention includethose that have been exposed to one or more chemical toxins, including,for example, a nerve toxin.

“Stemness” refers to the relative ability of any cell to act in a stemcell-like manner, i.e., the degree of toti-, pluri-, or oligopotentcyand expanded or indefinite self-renewal that any particular stem cellmay have.

Nucleases

Described herein are compositions, particularly nucleases, such asTALEs, homing endonucleases, CRISPR/Cas and/or Ttago guide RNAs, thatare useful for in vivo cleavage of a donor molecule carrying a transgeneand nucleases for cleavage of the genome of a cell such that thetransgene is integrated into the genome in a targeted manner. In certainembodiments, one or more of the nucleases are naturally occurring. Inother embodiments, one or more of the nucleases are non-naturallyoccurring, i.e., engineered in the DNA-binding molecule (also referredto as a DNA-binding domain) and/or cleavage domain. For example, theDNA-binding domain of a naturally-occurring nuclease may be altered tobind to a selected target site (e.g., a ZFP, TALE and/or sgRNA ofCRISPR/Cas that is engineered to bind to a selected target site). Inother embodiments, the nuclease comprises heterologous DNA-binding andcleavage domains (e.g., zinc finger nucleases; TAL-effector domain DNAbinding proteins; meganuclease DNA-binding domains with heterologouscleavage domains). In other embodiments, the nuclease comprises a systemsuch as the CRISPR/Cas of Ttago system.

A. DNA-Binding Domains

In certain embodiments, the composition and methods described hereinemploy a meganuclease (homing endonuclease) DNA-binding domain forbinding to the donor molecule and/or binding to the region of interestin the genome of the cell. Naturally-occurring meganucleases recognize15-40 base-pair cleavage sites and are commonly grouped into fourfamilies: the LAGLIDADG family (“LAGLIDADG” disclosed as SEQ ID NO: 26),the GIY-YIG family, the His-Cyst box family and the HNH family.Exemplary homing endonucleases include I-SceI, I-CeuI, PI-PspI, PI-Sce,I-SceIV, I-CsmI, I-PanI, I-SceII, I-PpoI, I-SceIII, I-CreI, I-TevI,I-TevII and I-TevIII. Their recognition sequences are known. See alsoU.S. Pat. Nos. 5,420,032; 6,833,252; Belfort et al. (1997) NucleicAcidsRes. 25:3379-3388; Dujon et al. (1989) Gene 82:115-118; Perler etal. (1994) Nucleic Acids Res. 22, 1125-1127; Jasin (1996) Trends Genet.12:224-228; Gimble et al. (1996) J. Mol. Biol. 263:163-180; Argast etal. (1998) J. Mol. Biol. 280:345-353 and the New England Biolabscatalogue.

In certain embodiments, the methods and compositions described hereinmake use of a nuclease that comprises an engineered (non-naturallyoccurring) homing endonuclease (meganuclease). The recognition sequencesof homing endonucleases and meganucleases such as I-SceI, I-CeuI,PI-PspI, PI-Sce, I-SceIV, I-CsmI, I-PanI, I-SceII, I-PpoI, I-SceIII,I-CreI, I-TevI, I-TevII and I-TevIII are known. See also U.S. Pat. Nos.5,420,032; 6,833,252; Belfort et al. (1997) Nucleic Acids Res.25:3379-3388; Dujon et al. (1989) Gene 82:115-118; Perler et al. (1994)Nucleic Acids Res. 22, 1125-1127; Jasin (1996) Trends Genet. 12:224-228;Gimble et al. (1996) J. Mol. Biol. 263:163-180; Argast et al. (1998) J.Mol. Biol. 280:345-353 and the New England Biolabs catalogue. Inaddition, the DNA-binding specificity of homing endonucleases andmeganucleases can be engineered to bind non-natural target sites. See,for example, Chevalier et al. (2002) Molec. Cell 10:895-905; Epinat etal. (2003) Nucleic Acids Res. 31:2952-2962; Ashworth et al. (2006)Nature 441:656-659; Paques et al. (2007) Current Gene Therapy 7:49-66;U.S. Patent Publication No. 20070117128. The DNA-binding domains of thehoming endonucleases and meganucleases may be altered in the context ofthe nuclease as a whole (i.e., such that the nuclease includes thecognate cleavage domain) or may be fused to a heterologous cleavagedomain.

In other embodiments, the DNA-binding domain of one or more of thenucleases used in the methods and compositions described hereincomprises a naturally occurring or engineered (non-naturally occurring)TAL effector DNA binding domain. See, e.g., U.S. Pat. No. 8,586,526,incorporated by reference in its entirety herein. The plant pathogenicbacteria of the genus Xanthomonas are known to cause many diseases inimportant crop plants. Pathogenicity of Xanthomonas depends on aconserved type III secretion (T3S) system which injects more than 25different effector proteins into the plant cell. Among these injectedproteins are transcription activator-like (TAL) effectors which mimicplant transcriptional activators and manipulate the plant transcriptome(see Kay et al (2007) Science 318:648-651). These proteins contain a DNAbinding domain and a transcriptional activation domain. One of the mostwell characterized TAL-effectors is AvrBs3 from Xanthomonas campestgrispv. Vesicatoria (see Bonas et al (1989) Mol Gen Genet 218: 127-136 andWO2010079430). TAL-effectors contain a centralized domain of tandemrepeats, each repeat containing approximately 34 amino acids, which arekey to the DNA binding specificity of these proteins. In addition, theycontain a nuclear localization sequence and an acidic transcriptionalactivation domain (for a review see Schornack S, et al (2006) J PlantPhysiol 163(3): 256-272). In addition, in the phytopathogenic bacteriaRalstonia solanacearum two genes, designated brg11 and hpx17 have beenfound that are homologous to the AvrBs3 family of Xanthomonas in the R.solanacearum biovar 1 strain GMI1000 and in the biovar 4 strain RS1000(See Heuer et al (2007) Appl and Envir Micro 73(13): 4379-4384). Thesegenes are 98.9% identical in nucleotide sequence to each other butdiffer by a deletion of 1,575 bp in the repeat domain of hpx17. However,both gene products have less than 40% sequence identity with AvrBs3family proteins of Xanthomonas. See, e.g., U.S. Pat. No. 8,586,526,incorporated by reference in its entirety herein.

Specificity of these TAL effectors depends on the sequences found in thetandem repeats. The repeated sequence comprises approximately 102 bp andthe repeats are typically 91-100% homologous with each other (Bonas etal, ibid). Polymorphism of the repeats is usually located at positions12 and 13 and there appears to be a one-to-one correspondence betweenthe identity of the hypervariable diresidues (RVDs) at positions 12 and13 with the identity of the contiguous nucleotides in the TAL-effector'starget sequence (see Moscou and Bogdanove, (2009) Science 326:1501 andBoch et al (2009) Science 326:1509-1512). Experimentally, the naturalcode for DNA recognition of these TAL-effectors has been determined suchthat an HD sequence at positions 12 and 13 leads to a binding tocytosine (C), NG binds to T, NI to A, C, G or T, NN binds to A or G, andING binds to T. These DNA binding repeats have been assembled intoproteins with new combinations and numbers of repeats, to makeartificial transcription factors that are able to interact with newsequences and activate the expression of a non-endogenous reporter genein plant cells (Boch et al, ibid). Engineered TAL proteins have beenlinked to a FokI cleavage half domain to yield a TAL effector domainnuclease fusion (TALEN) exhibiting activity in a yeast reporter assay(plasmid based target). See, e.g., U.S. Pat. No. 8,586,526; Christian etal ((2010)<Genetics epub 10.1534/genetics.110.120717).

In certain embodiments, the DNA binding domain of one or more of thenucleases used for in vivo cleavage and/or targeted cleavage of thegenome of a cell comprises a zinc finger protein. Preferably, the zincfinger protein is non-naturally occurring in that it is engineered tobind to a target site of choice. See, for example, See, for example,Beerli et al. (2002) Nature Biotechnol. 20:135-141; Pabo et al. (2001)Ann. Rev. Biochem. 70:313-340; Isalan et al. (2001) Nature Biotechnol.19:656-660; Segal et al. (2001) Curr. Opin. Biotechnol. 12:632-637; Chooet al. (2000) Curr. Opin. Struct. Biol. 10:411-416; U.S. Pat. Nos.6,453,242; 6,534,261; 6,599,692; 6,503,717; 6,689,558; 7,030,215;6,794,136; 7,067,317; 7,262,054; 7,070,934; 7,361,635; 7,253,273; andU.S. Patent Publication Nos. 2005/0064474; 2007/0218528; 2005/0267061,all incorporated herein by reference in their entireties.

An engineered zinc finger binding domain can have a novel bindingspecificity, compared to a naturally-occurring zinc finger protein.Engineering methods include, but are not limited to, rational design andvarious types of selection. Rational design includes, for example, usingdatabases comprising triplet (or quadruplet) nucleotide sequences andindividual zinc finger amino acid sequences, in which each triplet orquadruplet nucleotide sequence is associated with one or more amino acidsequences of zinc fingers which bind the particular triplet orquadruplet sequence. See, for example, co-owned U.S. Pat. Nos. 6,453,242and 6,534,261, incorporated by reference herein in their entireties.

Exemplary selection methods, including phage display and two-hybridsystems, are disclosed in U.S. Pat. Nos. 5,789,538; 5,925,523;6,007,988; 6,013,453; 6,410,248; 6,140,466; 6,200,759; and 6,242,568; aswell as WO 98/37186; WO 98/53057; WO 00/27878; and WO 01/88197. Inaddition, enhancement of binding specificity for zinc finger bindingdomains has been described, for example, in co-owned WO 02/077227.

In addition, as disclosed in these and other references, zinc fingerdomains and/or multi-fingered zinc finger proteins may be linkedtogether using any suitable linker sequences, including for example,linkers of 5 or more amino acids in length. See, also, U.S. Pat. Nos.8,772,453; 6,479,626; 6,903,185; and 7,153,949 for exemplary linkersequences-. The proteins described herein may include any combination ofsuitable linkers between the individual zinc fingers of the protein.

Selection of target sites; ZFPs and methods for design and constructionof fusion proteins (and polynucleotides encoding same) are known tothose of skill in the art and described in detail in U.S. Pat. Nos.6,140,081; 5,789,538; 6,453,242; 6,534,261; 5,925,523; 6,007,988;6,013,453; 6,200,759; WO 95/19431; WO 96/06166; WO 98/53057; WO98/54311; WO 00/27878; WO 01/60970 WO 01/88197; WO 02/099084; WO98/53058; WO 98/53059; WO 98/53060; WO 02/016536 and WO 03/016496.

In addition, as disclosed in these and other references, zinc fingerdomains and/or multi-fingered zinc finger proteins may be linkedtogether using any suitable linker sequences, including for example,linkers of 5 or more amino acids in length. See, also, U.S. Pat. Nos.6,479,626; 6,903,185; and 7,153,949 for exemplary linker sequences 6 ormore amino acids in length. The proteins described herein may includeany combination of suitable linkers between the individual zinc fingersof the protein.

In certain embodiments, the DNA-binding domain is part of a CRISPR/Casnuclease system, including, for example a single guide RNA (sgRNA). See,e.g., U.S. Pat. No. 8,697,359 and U.S. Patent Publication No.20150056705. The CRISPR (clustered regularly interspaced shortpalindromic repeats) locus, which encodes RNA components of the system,and the Cas (CRISPR-associated) locus, which encodes proteins (Jansen etal., 2002. Mol. Microbiol. 43: 1565-1575; Makarova et al., 2002. NucleicAcids Res. 30: 482-496; Makarova et al., 2006. Biol. Direct 1: 7; Haftet al., 2005. PLoSComput. Biol. 1: e60) make up the gene sequences ofthe CRISPR/Cas nuclease system. CRISPR loci in microbial hosts contain acombination of CRISPR-associated (Cas) genes as well as non-coding RNAelements capable of programming the specificity of the CRISPR-mediatednucleic acid cleavage.

The Type II CRISPR is one of the most well characterized systems andcarries out targeted DNA double-strand break in four sequential steps.First, two non-coding RNA, the pre-crRNA array and tracrRNA, aretranscribed from the CRISPR locus. Second, tracrRNA hybridizes to therepeat regions of the pre-crRNA and mediates the processing of pre-crRNAinto mature crRNAs containing individual spacer sequences. Third, themature crRNA:tracrRNA complex directs Cas9 to the target DNA viaWatson-Crick base-pairing between the spacer on the crRNA and theprotospacer on the target DNA next to the protospacer adjacent motif(PAM), an additional requirement for target recognition. Finally, Cas9mediates cleavage of target DNA to create a double-stranded break withinthe protospacer. Activity of the CRISPR/Cas system comprises of threesteps: (i) insertion of alien DNA sequences into the CRISPR array toprevent future attacks, in a process called ‘adaptation’, (ii)expression of the relevant proteins, as well as expression andprocessing of the array, followed by (iii) RNA-mediated interferencewith the alien nucleic acid. Thus, in the bacterial cell, several of theso-called ‘Cas’ proteins are involved with the natural function of theCRISPR/Cas system and serve roles in functions such as insertion of thealien DNA etc.

In certain embodiments, Cas protein may be a “functional derivative” ofa naturally occurring Cas protein. A “functional derivative” of a nativesequence polypeptide is a compound having a qualitative biologicalproperty in common with a native sequence polypeptide. “Functionalderivatives” include, but are not limited to, fragments of a nativesequence and derivatives of a native sequence polypeptide and itsfragments, provided that they have a biological activity in common witha corresponding native sequence polypeptide. A biological activitycontemplated herein is the ability of the functional derivative tohydrolyze a DNA substrate into fragments. The term “derivative”encompasses both amino acid sequence variants of polypeptide, covalentmodifications, and fusions thereof. Suitable derivatives of a Caspolypeptide or a fragment thereof include but are not limited tomutants, fusions, covalent modifications of Cas protein or a fragmentthereof. Cas protein, which includes Cas protein or a fragment thereof,as well as derivatives of Cas protein or a fragment thereof, may beobtainable from a cell or synthesized chemically or by a combination ofthese two procedures. The cell may be a cell that naturally produces Casprotein, or a cell that naturally produces Cas protein and isgenetically engineered to produce the endogenous Cas protein at a higherexpression level or to produce a Cas protein from an exogenouslyintroduced nucleic acid, which nucleic acid encodes a Cas that is sameor different from the endogenous Cas. In some cases, the cell does notnaturally produce Cas protein and is genetically engineered to produce aCas protein. Additional non-limiting examples of RNA guided nucleasesthat may be used in addition to and/or instead of Cas proteins includeClass 2 CRISPR proteins such as Cpfl. See, e.g., Zetsche et al. (2015)Cell 163:1-13.

In some embodiments, the DNA binding domain is part of a TtAgo system(see Swarts et al, ibid; Sheng et al, ibid). In eukaryotes, genesilencing is mediated by the Argonaute (Ago) family of proteins. In thisparadigm, Ago is bound to small (19-31 nt) RNAs. This protein-RNAsilencing complex recognizes target RNAs via Watson-Crick base pairingbetween the small RNA and the target and endonucleolytically cleaves thetarget RNA (Vogel (2014) Science 344:972-973). In contrast, prokaryoticAgo proteins bind to small single-stranded DNA fragments and likelyfunction to detect and remove foreign (often viral) DNA (Yuan et al.,(2005) Mol. Cell 19, 405; Olovnikov, et al. (2013) Mol. Cell 51, 594;Swarts et al., ibid). Exemplary prokaryotic Ago proteins include thosefrom Aquifex aeolicus, Rhodobacter sphaeroides, and Thermusthermophilus.

One of the most well-characterized prokaryotic Ago protein is the onefrom T. thermophilus (TtAgo; Swarts et al. ibid). TtAgo associates witheither 15 nt or 13-25 nt single-stranded DNA fragments with 5′ phosphategroups. This “guide DNA” bound by TtAgo serves to direct the protein-DNAcomplex to bind a Watson-Crick complementary DNA sequence in athird-party molecule of DNA. Once the sequence information in theseguide DNAs has allowed identification of the target DNA, the TtAgo-guideDNA complex cleaves the target DNA. Such a mechanism is also supportedby the structure of the TtAgo-guide DNA complex while bound to itstarget DNA (G. Sheng et al., ibid). Ago from Rhodobacter sphaeroides(RsAgo) has similar properties (Olivnikov et al. ibid).

Exogenous guide DNAs of arbitrary DNA sequence can be loaded onto theTtAgo protein (Swarts et al. ibid.). Since the specificity of TtAgocleavage is directed by the guide DNA, a TtAgo-DNA complex formed withan exogenous, investigator-specified guide DNA will therefore directTtAgo target DNA cleavage to a complementary investigator-specifiedtarget DNA. In this way, one may create a targeted double-strand breakin DNA. Use of the TtAgo-guide DNA system (or orthologous Ago-guide DNAsystems from other organisms) allows for targeted cleavage of genomicDNA within cells. Such cleavage can be either single- ordouble-stranded. For cleavage of mammalian genomic DNA, it would bepreferable to use of a version of TtAgo codon optimized for expressionin mammalian cells. Further, it might be preferable to treat cells witha TtAgo-DNA complex formed in vitro where the TtAgo protein is fused toa cell-penetrating peptide. Further, it might be preferable to use aversion of the TtAgo protein that has been altered via mutagenesis tohave improved activity at 37 degrees Celcius. Ago-RNA-mediated DNAcleavage could be used to effect a panopoly of outcomes including geneknock-out, targeted gene addition, gene correction, targeted genedeletion using techniques standard in the art for exploitation of DNAbreaks.

Thus, the nuclease comprises a DNA-binding domain in that specificallybinds to a target site in any gene into which it is desired to insert adonor (transgene).

B. Cleavage Domains

Any suitable cleavage domain can be operatively linked to a DNA-bindingdomain to form a nuclease. For example, ZFP DNA-binding domains havebeen fused to nuclease domains to create ZFNs—a functional entity thatis able to recognize its intended nucleic acid target through itsengineered (ZFP) DNA binding domain and cause the DNA to be cut near theZFP binding site via the nuclease activity. See, e.g., Kim et al. (1996)Proc Natl Acad Sci USA 93(3):1156-1160. More recently, ZFNs have beenused for genome modification in a variety of organisms. See, forexample, United States Patent Publications 20030232410; 20050208489;20050026157; 20050064474; 20060188987; 20060063231; and InternationalPublication WO 07/014275. Likewise, TALE DNA-binding domains have beenfused to nuclease domains to create TALENs. See, e.g., U.S. Pat. No.8,586,526. CRISPR/Cas nuclease systems comprising single guide RNAs(sgRNAs) that bind to DNA and associate with cleavage domains (e.g., Casdomains) to induce targeted cleavage have also been described. See,e.g., U.S. Pat. Nos. 8,697,359 and 8,932,814 and U.S. Patent PublicationNo. 20150056705.

As noted above, the cleavage domain may be heterologous to theDNA-binding domain, for example a zinc finger DNA-binding domain and acleavage domain from a nuclease or a TALEN DNA-binding domain and acleavage domain from a nuclease; a sgRNA DNA-binding domain and acleavage domain from a nuclease (CRISPR/Cas); and/or meganucleaseDNA-binding domain and cleavage domain from a different nuclease.Heterologous cleavage domains can be obtained from any endonuclease orexonuclease. Exemplary endonucleases from which a cleavage domain can bederived include, but are not limited to, restriction endonucleases andhoming endonucleases. See, for example, 2002-2003 Catalogue, New EnglandBiolabs, Beverly, Mass.; and Belfort et al. (1997) Nucleic Acids Res.25:3379-3388. Additional enzymes which cleave DNA are known (e.g., S1Nuclease; mung bean nuclease; pancreatic DNase I; micrococcal nuclease;yeast HO endonuclease; see also Linn et al. (eds.) Nucleases, ColdSpring Harbor Laboratory Press, 1993). One or more of these enzymes (orfunctional fragments thereof) can be used as a source of cleavagedomains and cleavage half-domains.

Similarly, a cleavage half-domain can be derived from any nuclease orportion thereof, as set forth above, that requires dimerization forcleavage activity. In general, two fusion proteins are required forcleavage if the fusion proteins comprise cleavage half-domains.Alternatively, a single protein comprising two cleavage half-domains canbe used. The two cleavage half-domains can be derived from the sameendonuclease (or functional fragments thereof), or each cleavagehalf-domain can be derived from a different endonuclease (or functionalfragments thereof). In addition, the target sites for the two fusionproteins are preferably disposed, with respect to each other, such thatbinding of the two fusion proteins to their respective target sitesplaces the cleavage half-domains in a spatial orientation to each otherthat allows the cleavage half-domains to form a functional cleavagedomain, e.g., by dimerizing. Thus, in certain embodiments, the nearedges of the target sites are separated by 5-8 nucleotides or by 15-18nucleotides. However any integral number of nucleotides or nucleotidepairs can intervene between two target sites (e.g., from 2 to 50nucleotide pairs or more). In general, the site of cleavage lies betweenthe target sites.

Restriction endonucleases (restriction enzymes) are present in manyspecies and are capable of sequence-specific binding to DNA (at arecognition site), and cleaving DNA at or near the site of binding.Certain restriction enzymes (e.g., Type IIS) cleave DNA at sites removedfrom the recognition site and have separable binding and cleavagedomains. For example, the Type IIS enzyme Fok I catalyzesdouble-stranded cleavage of DNA, at 9 nucleotides from its recognitionsite on one strand and 13 nucleotides from its recognition site on theother. See, for example, U.S. Pat. Nos. 5,356,802; 5,436,150 and5,487,994; as well as Li et al. (1992) Proc. Natl. Acad. Sci. USA89:4275-4279; Li et al. (1993) Proc. Natl. Acad. Sci. USA 90:2764-2768;Kim et al. (1994a) Proc. Natl. Acad. Sci. USA 91:883-887; Kim et al.(1994b) J. Biol. Chem. 269:31,978-31,982. Thus, in one embodiment,fusion proteins comprise the cleavage domain (or cleavage half-domain)from at least one Type IIS restriction enzyme and one or more zincfinger binding domains, which may or may not be engineered.

An exemplary Type IIS restriction enzyme, whose cleavage domain isseparable from the binding domain, is Fok I. This particular enzyme isactive as a dimer. Bitinaite et al. (1998) Proc. Natl. Acad. Sci. USA95: 10,570-10,575. Accordingly, for the purposes of the presentdisclosure, the portion of the Fok I enzyme used in the disclosed fusionproteins is considered a cleavage half-domain. Thus, for targeteddouble-stranded cleavage and/or targeted replacement of cellularsequences using zinc finger-Fok I fusions, two fusion proteins, eachcomprising a FokI cleavage half-domain, can be used to reconstitute acatalytically active cleavage domain. Alternatively, a singlepolypeptide molecule containing a zinc finger binding domain and two FokI cleavage half-domains can also be used. Parameters for targetedcleavage and targeted sequence alteration using zinc finger-Fok Ifusions are provided elsewhere in this disclosure.

A cleavage domain or cleavage half-domain can be any portion of aprotein that retains cleavage activity, or that retains the ability tomultimerize (e.g., dimerize) to form a functional cleavage domain.

Exemplary Type IIS restriction enzymes are described in U.S. Pat. No.7,888,121, incorporated herein in its entirety. Additional restrictionenzymes also contain separable binding and cleavage domains, and theseare contemplated by the present disclosure. See, for example, Roberts etal. (2003) Nucleic Acids Res. 31:418-420.

In certain embodiments, the cleavage domain comprises one or moreengineered cleavage half-domain (also referred to as dimerization domainmutants) that minimize or prevent homodimerization, as described, forexample, in U.S. Pat. Nos. 8,772,453; 8,623,618; 8,409,861; 8,034,598;7,914,796; and 7,888,121, the disclosures of all of which areincorporated by reference in their entireties herein. Amino acidresidues at positions 446, 447, 479, 483, 484, 486, 487, 490, 491, 496,498, 499, 500, 531, 534, 537, and 538 of FokI are all targets forinfluencing dimerization of the FokI cleavage half-domains.

Exemplary engineered cleavage half-domains of FokI that form obligateheterodimers include a pair in which a first cleavage half-domainincludes mutations at amino acid residues at positions 490 and 538 ofFokI and a second cleavage half-domain includes mutations at amino acidresidues 486 and 499.

Thus, in one embodiment, a mutation at 490 replaces Glu (E) with Lys(K); the mutation at 538 replaces Iso (I) with Lys (K); the mutation at486 replaced Gln (Q) with Glu (E); and the mutation at position 499replaces Iso (I) with Lys (K). Specifically, the engineered cleavagehalf-domains described herein were prepared by mutating positions 490(E→K) and 538 (I→K) in one cleavage half-domain to produce an engineeredcleavage half-domain designated “E490K:I538K” and by mutating positions486 (Q→E) and 499 (I→L) in another cleavage half-domain to produce anengineered cleavage half-domain designated “Q486E:I499L”. The engineeredcleavage half-domains described herein are obligate heterodimer mutantsin which aberrant cleavage is minimized or abolished. U.S. Pat. Nos.7,914,796 and 8,034,598, the disclosures of which are incorporated byreference in their entireties. In certain embodiments, the engineeredcleavage half-domain comprises mutations at positions 486, 499 and 496(numbered relative to wild-type FokI), for instance mutations thatreplace the wild type Gln (Q) residue at position 486 with a Glu (E)residue, the wild type Iso (I) residue at position 499 with a Leu (L)residue and the wild-type Asn (N) residue at position 496 with an Asp(D) or Glu (E) residue (also referred to as a “ELD” and “ELE” domains,respectively). In other embodiments, the engineered cleavage half-domaincomprises mutations at positions 490, 538 and 537 (numbered relative towild-type FokI), for instance mutations that replace the wild type Glu(E) residue at position 490 with a Lys (K) residue, the wild type Iso(I) residue at position 538 with a Lys (K) residue, and the wild-typeHis (H) residue at position 537 with a Lys (K) residue or a Arg (R)residue (also referred to as “KKK” and “KKR” domains, respectively). Inother embodiments, the engineered cleavage half-domain comprisesmutations at positions 490 and 537 (numbered relative to wild-typeFokI), for instance mutations that replace the wild type Glu (E) residueat position 490 with a Lys (K) residue and the wild-type His (H) residueat position 537 with a Lys (K) residue or a Arg (R) residue (alsoreferred to as “KIK” and “KIR” domains, respectively). See, e.g., U.S.Pat. No. 8,772,453. In other embodiments, the engineered cleavage halfdomain comprises the “Sharkey” and/or “Sharkey′” mutations (see Guo etal, (2010) J. Mol. Biol. 400(1):96-107).

Engineered cleavage half-domains described herein can be prepared usingany suitable method, for example, by site-directed mutagenesis ofwild-type cleavage half-domains (Fok I) as described in U.S. PatentPublication Nos. 20050064474; 20080131962; and 20110201055.

Alternatively, nucleases may be assembled in vivo at the nucleic acidtarget site using so-called “split-enzyme” technology (see, e.g. U.S.Patent Publication No. 20090068164). Components of such split enzymesmay be expressed either on separate expression constructs, or can belinked in one open reading frame where the individual components areseparated, for example, by a self-cleaving 2A peptide or IRES sequence.Components may be individual zinc finger binding domains or domains of ameganuclease nucleic acid binding domain.

Nucleases can be screened for activity prior to use, for example in ayeast-based chromosomal system as described in U.S. Pat. No. 8,563,314.Expression of the nuclease may be under the control of a constitutivepromoter or an inducible promoter, for example the galactokinasepromoter which is activated (de-repressed) in the presence of raffinoseand/or galactose and repressed in presence of glucose.

The Cas9 related CRISPR/Cas system comprises two RNA non-codingcomponents: tracrRNA and a pre-crRNA array containing nuclease guidesequences (spacers) interspaced by identical direct repeats (DRs). Touse a CRISPR/Cas system to accomplish genome engineering, both functionsof these RNAs must be present (see Cong et al, (2013) Sciencexpress1/10.1126/science 1231143). In some embodiments, the tracrRNA andpre-crRNAs are supplied via separate expression constructs or asseparate RNAs. In other embodiments, a chimeric RNA is constructed wherean engineered mature crRNA (conferring target specificity) is fused to atracrRNA (supplying interaction with the Cas9) to create a chimericcr-RNA-tracrRNA hybrid (also termed a single guide RNA). (see Jinek ibidand Cong, ibid).

Target Sites

As described in detail above, DNA domains can be engineered to bind toany sequence of choice. An engineered DNA-binding domain can have anovel binding specificity, compared to a naturally-occurring DNA-bindingdomain. Engineering methods include, but are not limited to, rationaldesign and various types of selection. Rational design includes, forexample, using databases comprising triplet (or quadruplet) nucleotidesequences and individual zinc finger amino acid sequences, in which eachtriplet or quadruplet nucleotide sequence is associated with one or moreamino acid sequences of zinc fingers which bind the particular tripletor quadruplet sequence. See, for example, co-owned U.S. Pat. Nos.6,453,242 and 6,534,261, incorporated by reference herein in theirentireties. Rational design of TAL-effector domains can also beperformed. See, e.g., U.S. Pat. No. 8,586,526.

Exemplary selection methods applicable to DNA-binding domains, includingphage display and two-hybrid systems, are disclosed in U.S. Pat. Nos.8,586,526; 5,789,538; 5,925,523; 6,007,988; 6,013,453; 6,410,248;6,140,466; 6,200,759; and 6,242,568; as well as WO 98/37186; WO98/53057; WO 00/27878; WO 01/88197 and GB 2,338,237. In addition,enhancement of binding specificity for zinc finger binding domains hasbeen described, for example, in co-owned WO 02/077227.

Selection of target sites; nucleases and methods for design andconstruction of fusion proteins (and polynucleotides encoding same) areknown to those of skill in the art and described in detail in U.S.Patent Application Publication Nos. 20050064474 and 20060188987,incorporated by reference in their entireties herein.

In addition, as disclosed in these and other references, DNA-bindingdomains (e.g., multi-fingered zinc finger proteins) may be linkedtogether using any suitable linker sequences, including for example,linkers of 5 or more amino acids. See, e.g., U.S. Pat. Nos. 6,479,626;6,903,185; and 7,153,949 for exemplary linker sequences 6 or more aminoacids in length. The proteins described herein may include anycombination of suitable linkers between the individual DNA-bindingdomains of the protein. See, also, U.S. Pat. No. 8,586,526.

As noted above, the DNA-binding domains of the nucleases may be targetedto any gene. In certain embodiments, the nuclease (DNA-binding domaincomponent) is targeted to an endogenous albumin gene. See, e.g., U.S.Patent Publication Nos. 20130177983; 20130177960 and 20150056705. Inother embodiments, the nuclease targets another “safe harbor” locus,which includes, by way of example only, the AAVS1, HPRT, and CCR5 genesin human cells, and Rosa26 in murine cells (see, e.g., U.S. Pat. Nos.7,888,121; 7,972,854; 7,914,796; 7,951,925; 8,110,379; 8,409,861;8,586,526; U.S. Patent Publications 20030232410; 20050208489;20050026157; 20060063231; 20080159996; 201000218264; 20120017290;20110265198; 20130137104; 20130122591) and the Zp15 locus in plants (seeU.S. Pat. No. 8,329,986).

Donors

The present disclosure relates to nuclease-mediated targeted integrationof an exogenous sequence into the genome of an HSC/PC. As noted above,insertion of an exogenous sequence (also called a “donor sequence” or“donor” or “transgene”), for example for correction of a mutant gene orfor increased expression of a wild-type gene or for expression of atransgene. It will be readily apparent that the donor sequence istypically not identical to the genomic sequence where it is placed. Adonor sequence can contain a non-homologous sequence flanked by tworegions of homology to allow for efficient HDR at the location ofinterest. Additionally, donor sequences can comprise a vector moleculecontaining sequences that are not homologous to the region of interestin cellular chromatin. A donor molecule can contain several,discontinuous regions of homology to cellular chromatin. For example,for targeted insertion of sequences not normally present in a region ofinterest, said sequences can be present in a donor nucleic acid moleculeand flanked by regions of homology to sequence in the region ofinterest.

Described herein are methods of targeted insertion of anypolynucleotides for insertion into a chosen location. Polynucleotidesfor insertion can also be referred to as “exogenous” polynucleotides,“donor” polynucleotides or molecules or “transgenes.” The donorpolynucleotide can be DNA or RNA, single-stranded and/or double-strandedand can be introduced into a cell in linear or circular form. See, e.g.,U.S. Patent Publication Nos. 20100047805 and 20110207221. The donorsequence(s) are preferably contained within a DNA MC, which may beintroduced into the cell in circular or linear form. If introduced inlinear form, the ends of the donor sequence can be protected (e.g., fromexonucleolytic degradation) by methods known to those of skill in theart. For example, one or more dideoxynucleotide residues are added tothe 3′ terminus of a linear molecule and/or self-complementaryoligonucleotides are ligated to one or both ends. See, for example,Chang et al. (1987) Proc. Natl. Acad. Sci. USA 84:4959-4963; Nehls etal. (1996) Science 272:886-889. Additional methods for protectingexogenous polynucleotides from degradation include, but are not limitedto, addition of terminal amino group(s) and the use of modifiedinternucleotide linkages such as, for example, phosphorothioates,phosphoramidates, and O-methyl ribose or deoxyribose residues.

A polynucleotide can be introduced into a cell as part of a vectormolecule having additional sequences such as, for example, replicationorigins, promoters and genes encoding antibiotic resistance. Moreover,donor polynucleotides can be introduced as naked nucleic acid, asnucleic acid complexed with an agent such as a liposome or poloxamer, orcan be delivered by viruses (e.g., adenovirus, AAV, herpesvirus,retrovirus, lentivirus and integrase defective lentivirus (IDLV)).

In certain embodiments, the double-stranded donor includes sequences(e.g., coding sequences, also referred to as transgenes) greater than 1kb in length, for example between 2 and 200 kb, between 2 and 10 kb (orany value therebetween). The double-stranded donor also includes atleast one nuclease target site, for example. In certain embodiments, thedonor includes at least 2 target sites, for example for a pair of ZFNsor TALENs. Typically, the nuclease target sites are outside thetransgene sequences, for example, 5′ and/or 3′ to the transgenesequences, for cleavage of the transgene. The nuclease cleavage site(s)may be for any nuclease(s). In certain embodiments, the nuclease targetsite(s) contained in the double-stranded donor are for the samenuclease(s) used to cleave the endogenous target into which the cleaveddonor is integrated via homology-independent methods.

The donor can be inserted so that its expression is driven by theendogenous promoter at the integration site, namely the promoter thatdrives expression of the endogenous gene into which the donor isinserted (e.g., albumin or HPRT). However, it will be apparent that thedonor may comprise a promoter and/or enhancer, for example aconstitutive promoter or an inducible or tissue specific promoter.

The donor molecule may be inserted into an endogenous gene such thatall, some or none of the endogenous gene (e.g., albumin) is expressed.In other embodiments, the transgene (e.g., with or without albuminencoding sequences) is integrated into any endogenous locus, for examplea safe-harbor locus. See, e.g., U.S. patent publications 20080299580;20080159996 and 201000218264.

Furthermore, although not required for expression, exogenous sequencesmay also include transcriptional or translational regulatory sequences,for example, promoters, enhancers, insulators, internal ribosome entrysites, sequences encoding 2A peptides and/or polyadenylation signals.Additionally, splice acceptor sequences may be included. Exemplarysplice acceptor site sequences are known to those of skill in the artand include, by way of example only, CTGACCTCTTCTCTTCCTCCCACAG, (SEQ IDNO:1) (from the human HBB gene) and TTTCTCTCCACAG (SEQ ID NO:2) (fromthe human Immunoglobulin-gamma gene).

In certain embodiments, the exogenous sequence (donor) comprises afusion of a protein of interest and, as its fusion partner, anextracellular domain of a membrane protein, causing the fusion proteinto be located on the surface of the cell. This allows the proteinencoded by the transgene to potentially act in the serum. In the case oftreatment for an LSD, the enzyme encoded by the transgene fusion wouldbe able to act on the metabolic products that are accumulating in theserum from its location on the surface of the cell (e.g., RBC). Inaddition, if the RBC is engulfed by a splenic macrophage as is thenormal course of degradation, the lysosome formed when the macrophageengulfs the cell would expose the membrane bound fusion protein to thehigh concentrations of metabolic products in the lysosome at the pH morenaturally favorable to that enzyme. Non-limiting examples of potentialfusion partners are shown below in Table 1.

TABLE 1 Examples of potential fusion partners Name Activity Band 3 Aniontransporter, makes up to 25% of the RBC membrane surface proteinAquaporin 1 water transporter Glut1 glucose and L-dehydroascorbic acidtransporter Kidd antigen protein urea transporter RhAG gas transporterATP1A1, ATP1B1 Na+/K+-ATPase ATP2B1, ATP2B2, ATP2B3, Ca2+-ATPase ATP2B4NKCC1, NKCC2 Na+ K+ 2Cl−-cotransporter SLC12A3 Na+—Cl−-cotransporterSLC12A1, SLA12A2 Na—K-cotransporter KCC1 K—Cl cotransporter KCNN4 GardosChannel

Lysosomal storage diseases typically fall into five classes. Theseclasses are shown below in Table 2 along with specific examples of thediseases. Thus, the donor molecules described herein can includesequences coding for one or more enzymes lacking or deficient insubjects with lysosomal storage diseases, including but not limited tothe proteins shown in Table 2.

TABLE 2 Lysosomal Storage Diseases Disease Protein Disease AssociatedGene Accumulated product 1. DEFECTS IN GLYCAN DEGRADATION I. Defects inglycoprotein degradation α-Sialidase (neuraminidase) Sialidosis NEU1sialidated glycopeptides and oligosaccharides Cathepsin AGalactosialidosis CTSA polysaccharide lysosomal alpha- α-MannosidosisMAN2B1 mannose-rich mannosidase glycoproteins and oligosaccharideslysosomal beta- β-Mannosidosis MANBA mannosidase GlycosylasparaginaseAspartylglucosaminuria AGA glycoasparagines Alpha L FucosidaseFucosidosis FUCA1 fucose α-N-Acetylglucosaminidase Sanfilippo syndrome BNAGLU glycosaminoglycan II. Defects in glycolipid degradation A. GM1Ganglioside β-Galactosidase GM1 gangliosidosis/MPS IVB GLB1 keratansulfate β-Hexosaminidase α- GM2-gangliosidosis (Tay-Sachs) HEXA GM2ganglioside subunit β-Hexosaminidase β- GM2-gangliosidosis (Sandhoff)HEXB GM2 ganglioside subunit GM2 activator protein GM2 gangliosidosisGM2A GM2 ganglioside Glucocerebrosidase Gaucher disease GBAglucocerebroside Saposin C Gaucher disease (atypical) PSAPglucocerebroside B. Defects in the degradation of sulfatideArylsulfatase A Metachromatic leukodystrophy ARSA sulphatide Saposin BMetachromatic leukodystrophy PSAP sulphatide Formyl-Glycin generatingMultiple sulfatase deficiency SUMF1 sulfated lipids enzymeβ-Galactosylceramidase Globoid cell leukodystrophy GALCgalactocerebroside (Krabbe) C. Defects in degradation ofglobotriaosylceramide α-Galactosidase A Fabry GLA globotriaosylcera-mideIII. Defects in degradation of Glycosaminoglycan (Mucopolysaccharidoses)A. Degradation of heparan sulphate Iduronate sulfatase MPS II (Hunter)IDS Dermatan sulfate, Heparan sulfate Iduronidase MPS 1 (Hurler, Scheie)IDUA Dermatan sulfate, Heparan sulfate Heparan N-sulfatase MPS IIIa(Sanfilippo A) SGSH Heparan sulfate Acetyl-CoA transferase MPS IIIc(Sanfilippo C) HGSNAT Heparan sulfate N-acetyl glucosaminidase MPS IIIb(Sanfilippo B) NAGLU Heparan sulfate β-glucuronidase MPS VII (Sly) GUSBN-acetyl glucosamine 6- MPS IIId (Sanfilippo D) GNS Heparan sulfatesulfatase B. Degradation of other mucopolysaccharides B-GalactosidaseMPS VIB (Morquio B) GLB1 Keratan sulfate, Galactose 6-sulfatase MPS IVA(Morquio A) GALNS Keratan sulfate, Chondroitin 6-sulfate HyaluronidaseMPS IX HYAL1 Hyaluronic acid C. Defects in degradation of glycogenα-Glucosidase Pompe GAA Glycogen 2. DEFECTS IN LIPID DEGRADATION I.Defects in degradation of sphingomyelin Acid sphingomyelinase NiemannPick type A SMPD1 sphingomyelin Acid ceramidase Farberlipogranulomatosis ASAH1 nonsulfonated acid mucopolysaccharide II.Defects in degradation of triglycerides and cholesteryls ester Acidlipase Wolman and cholesteryl ester LIPA cholesteryl esters storagedisease 3. DEFECTS IN PROTEIN DEGRADATION Cathepsin K PycnodystostosisCTSK Tripeptidyl peptidase Ceroide lipofuscinosis PPT2 Palmitoyl-proteinCeroide lipofuscinosis PPT1 thioesterase 4. DEFECTS IN LYSOSOMALTRANSPORTERS Cystinosin (cystin transport) Cystinosis CTNS Sialin(sialic acid transport) Salla disease SLC17A5 N-acetylneuraminic acid 5.DEFECTS IN LYSOSOMAL TRAFFICKING PROTEINS Phosphotransferase γ-Mucolipidosis III (I-cell) GNPTG subunit Mucolipin-1(cationMucolipidosis MCOLN1 channel) LYSOSOME-ASSOCIATED Danon LAMP2 MEMBRANEPROTEIN 2 Niemann-Pick disease, type Niemann Pick type C NPC1 LDLcholesterol C1 palmitoyl-protein Ceroid lipofuscinosis (Batten CLN3autofluorescent thioesterase-1 Disease) lipopigment storage materialneuronal ceroid Ceroid lipofuscinosis 6 CLN 6 lipofuscinosis-6 neuronalceroid Ceroid lipofuscinosis 8 CLN 8 lipofuscinosis-8 LYSOSOMALTRAFFICKING Chediak-Higashi LYST REGULATOR Myocilin Griscelli Type 1MYOC RAS-associated protein 27A Griscelli Type 2 RAB27A MelanophilinGriscelli Type 3 MLPH or MYO5A AP3 β-subunit Hermansky Pudliak AP3B1ceroid

In certain embodiments, the donor comprises a transgene that encodes aprotein lacking of deficient in Hurler, Hunter and/or Gaucher LSDs, forexample, iduronidase, iduronate-2-sulfatase and/or glucocerebrosidase.Following administration to the subject, for example to the liver viaintravenous injection through the portal vein, the transgene istypically expressed at much higher levels in the liver and is detectablein secondary tissues including plasma than subjects not subject tonuclease-mediated integration. Levels of the therapeutic protein in thesubject's tissues (e.g., plasma) are 2-4 fold (or any valuetherebetween), 2-10 fold (or any value therebetween), 10-100 fold (orany value therebetween) or more than in the untreated subjects.

In some cases, the donor may be an endogenous gene that has beenmodified. Although antibody response to enzyme replacement therapyvaries with respect to the specific therapeutic enzyme in question andwith the individual patient, a significant immune response has been seenin many LSD patients being treated with enzyme replacement. In addition,the relevance of these antibodies to the efficacy of treatment is alsovariable (see Katherine Ponder, (2008) J Clin Invest 118(8):2686). Thus,the methods and compositions of the current invention can comprise theuse of donor molecules whose sequence has been altered by functionallysilent amino acid changes at sites known to be priming epitopes forendogenous immune responses, such that the polypeptide produced by sucha donor is less immunogenic.

LSD patients often have neurological sequelae due the lack of themissing enzyme in the brain. Unfortunately, it is often difficult todeliver therapeutics to the brain via the blood due to theimpermeability of the blood brain barrier. Thus, the methods andcompositions of the invention may be used in conjunction with methods toincrease the delivery of the therapeutic into the brain. There are somemethods that cause a transient opening of the tight junctions betweencells of the brain capillaries. Examples include transient osmoticdisruption through the use of an intracarotid administration of ahypertonic mannitol solution, the use of focused ultrasound and theadministration of a bradykinin analogue. Alternatively, therapeutics canbe designed to utilize receptors or transport mechanisms for specifictransport into the brain. Examples of specific receptors that may beused include the transferrin receptor, the insulin receptor or thelow-density lipoprotein receptor related proteins 1 and 2 (LRP-1 andLRP-2). LRP is known to interact with a range of secreted proteins suchas apoE, tPA, PAI-1 etc, and so fusing a recognition sequence from oneof these proteins for LRP may facilitate transport of the enzyme intothe brain, following expression in the liver of the therapeutic proteinand secretion into the blood stream (see Gabathuler, (2010) ibid). Thetransgenes carried on the donor sequences described herein may beisolated from plasmids, cells or other sources using standard techniquesknown in the art such as PCR. Donors for use can include varying typesof topology, including circular supercoiled, circular relaxed, linearand the like. Alternatively, they may be chemically synthesized usingstandard oligonucleotide synthesis techniques. In addition, donors maybe methylated or lack methylation. Donors may be in the form ofbacterial or yeast artificial chromosomes (BACs or YACs).

The double-stranded donor polynucleotides described herein may includeone or more non-natural bases and/or backbones. In particular, insertionof a donor molecule with methylated cytosines may be carried out usingthe methods described herein to achieve a state of transcriptionalquiescence in a region of interest.

In certain embodiments, the exogenous sequences can comprise a markergene (described above), allowing selection of cells that have undergonetargeted integration, and a linked sequence encoding an additionalfunctionality. Non-limiting examples of marker genes include GFP, drugselection marker(s) and the like.

Construction of such expression cassettes, following the teachings ofthe present specification, utilizes methodologies well known in the artof molecular biology (see, for example, Ausubel or Maniatis). Before useof the expression cassette to generate a transgenic animal, theresponsiveness of the expression cassette to the stress-inducerassociated with selected control elements can be tested by introducingthe expression cassette into a suitable cell line (e.g., primary cells,transformed cells, or immortalized cell lines).

Targeted insertion of non-coding nucleic acid sequence may also beachieved. Sequences encoding antisense RNAs, RNAi, shRNAs and micro RNAs(miRNAs) may also be used for targeted insertions.

In additional embodiments, the donor nucleic acid may comprisenon-coding sequences that are specific target sites for additionalnuclease designs. Subsequently, additional nucleases may be expressed incells such that the original donor molecule is cleaved and modified byinsertion of another donor molecule of interest. In this way,reiterative integrations of donor molecules may be generated allowingfor trait stacking at a particular locus of interest or at a safe harborlocus.

Cells

Also provided herein are genetically modified cells, for example, livercells or stem cells comprising a transgene encoding a protein lacking ordeficient in a lysosomal storage disease, including cells produced bythe methods described herein. The transgene is integrated in a targetedmanner into the cell's genome using one or more nucleases. Unlike randomintegration, targeted integration ensures that the transgene isintegrated into a specified gene. The transgene may be integratedanywhere in the target gene. In certain embodiments, the transgene isintegrated at or near the nuclease binding and/or cleavage site, forexample, within 1-300 (or any number of base pairs therebetween) basepairs upstream or downstream of the site of cleavage and/or bindingsite, more preferably within 1-100 base pairs (or any number of basepairs therebetween) of either side of the cleavage and/or binding site,even more preferably within 1 to 50 base pairs (or any number of basepairs therebetween) of either side of the cleavage and/or binding site.In certain embodiments, the integrated sequence does not include anyvector sequences (e.g., viral vector sequences). In certain embodiments,the cells comprise a modification (e.g., insertion and/or deletion) madeby a nuclease as described herein such that the modification is withinan intron of an HPRT gene, for example intron 1. In certain embodiments,the modification is at or near (e.g., 1-300 base pairs or any number ofbase pairs therebetween) SEQ ID NO:24 or 25. In other embodiments, themodification is 1-100 (or any number of base pairs therebetween) basepairs of SEQ ID NO:24 or 25. In certain embodiments, the modification iswithin SEQ ID NO:24 and/or SEQ ID NO:25, for example a modification of 1or more base pairs in either SEQ ID NO:24 or 25.

Any cell type can be genetically modified as described herein tocomprise a transgene, including but not limited to cells or cell lines.Other non-limiting examples of genetically modified cells as describedherein include T-cells (e.g., CD4+, CD3+, CD8+, etc.); dendritic cells;B-cells; autologous (e.g., patient-derived). In certain embodiments, thecells are liver cells and are modified in vivo. In certain embodiments,the cells are stem cells, including heterologous pluripotent, totipotentor multipotent stem cells (e.g., CD34+ cells, induced pluripotent stemcells (iPSCs), embryonic stem cells or the like). In certainembodiments, the cells as described herein are stem cells derived frompatient.

The cells as described herein are useful in treating and/or preventinglysosomal storage disorders in a subject with the disorder, for example,by in vivo therapies. Ex vivo therapies are also provided, for examplewhen the nuclease-modified cells can be expanded and then reintroducedinto the patient using standard techniques. See, e.g., Tebas et al(2014) New Eng J Med 370(10):901. In the case of stem cells, afterinfusion into the subject, in vivo differentiation of these precursorsinto cells expressing the functional protein (from the inserted donor)also occurs.

Pharmaceutical compositions comprising the cells as described herein arealso provided. In addition, the cells may be cryopreserved prior toadministration to a patient.

Delivery

The nucleases, polynucleotides encoding these nucleases, donorpolynucleotides and compositions comprising the proteins and/orpolynucleotides described herein may be delivered in vivo or ex vivo byany suitable means into any cell type.

Thus, the instant disclosure includes in vivo or ex vivo treatment ofdiseases and conditions that are amenable to insertion of a transgenesencoding a therapeutic protein, for example treatment of LSD(s) vianuclease-mediated integration of proteins (enzymes) lacking of deficientin the LSD(s). The compositions are administered to a human patient inan amount effective to obtain the desired concentration of thetherapeutic polypeptide in the serum or the target organ or cells.Administration can be by any means in which the polynucleotides aredelivered to the desired target cells. For example, both in vivo and exvivo methods are contemplated. Intravenous injection to the portal veinis a preferred method of administration. Other in vivo administrationmodes include, for example, direct injection into the lobes of the liveror the biliary duct and intravenous injection distal to the liver,including through the hepatic artery, direct injection in to the liverparenchyma, injection via the hepatic artery, and/or retrogradeinjection through the biliary tree. Ex vivo modes of administrationinclude transduction in vitro of resected hepatocytes or other cells ofthe liver, followed by infusion of the transduced, resected hepatocytesback into the portal vasculature, liver parenchyma or biliary tree ofthe human patient, see e.g., Grossman et al., (1994) Nature Genetics,6:335-341.

Methods of delivering nucleases and/or donors as described herein aredescribed, for example, in U.S. Pat. Nos. 6,453,242; 6,503,717;6,534,261; 6,599,692; 6,607,882; 6,689,558; 6,824,978; 6,933,113;6,979,539; 7,013,219; and 7,163,824, the disclosures of all of which areincorporated by reference herein in their entireties.

Nucleases and/or donor constructs as described herein may also bedelivered using vectors containing sequences encoding one or more of theZFN(s), TALEN(s), CRIPSR/Cas systems or Ttago systems. Any vectorsystems may be used including, but not limited to, plasmid vectors,retroviral vectors, lentiviral vectors, adenovirus vectors, poxvirusvectors; herpesvirus vectors and adeno-associated virus (AAV) vectors,etc. See, also, U.S. Pat. Nos. 6,534,261; 6,607,882; 6,824,978;6,933,113; 6,979,539; 7,013,219; and 7,163,824, incorporated byreference herein in their entireties. Furthermore, it will be apparentthat any of these vectors may comprise one or more of the sequencesneeded for treatment. Thus, when one or more nucleases and a donorconstruct are introduced into the cell, the nucleases and/or donorpolynucleotide may be carried on the same vector or on different vectors(DNA MC(s)). When multiple vectors are used, each vector may comprise asequence encoding one or multiple nucleases and/or donor constructs.

Conventional viral and non-viral based gene transfer methods can be usedto introduce nucleic acids encoding nucleases and donor constructs incells (e.g., mammalian cells) and target tissues. Non-viral vectordelivery systems include DNA or RNA plasmids, DNA MCs, naked nucleicacid, and nucleic acid complexed with a delivery vehicle such as aliposome, other nanoparticle or poloxamer. Viral vector delivery systemsinclude DNA and RNA viruses, which have either episomal or integratedgenomes after delivery to the cell. For a review of in vivo delivery ofengineered DNA-binding proteins and fusion proteins comprising thesebinding proteins, see, e.g., Rebar (2004) Expert Opinion Invest. Drugs13(7):829-839; Rossi et al. (2007) Nature Biotech. 25(12):1444-1454 aswell as general gene delivery references such as Anderson, Science256:808-813 (1992); Nabel & Feigner, TIBTECH 11:211-217 (1993); Mitani &Caskey, TIBTECH 11:162-166 (1993); Dillon, TIBTECH 11:167-175 (1993);Miller, Nature 357:455-460 (1992); Van Brunt, Biotechnology6(10):1149-1154 (1988); Vigne, Restorative Neurology and Neuroscience8:35-36 (1995); Kremer & Perricaudet, British Medical Bulletin51(1):31-44 (1995); Haddada et al., in Current Topics in Microbiologyand Immunology Doerfler and Böhm (eds.) (1995); and Yu et al., GeneTherapy 1:13-26 (1994).

Methods of non-viral delivery of nucleic acids include electroporation,lipofection, microinjection, biolistics, virosomes, liposomes,immunoliposomes, polycation or lipid:nucleic acid conjugates,nanoparticles, naked DNA, artificial virions, and agent-enhanced uptakeof DNA. Sonoporation using, e.g., the Sonitron 2000 system (Rich-Mar)can also be used for delivery of nucleic acids.

Additional exemplary nucleic acid delivery systems include thoseprovided by AmaxaBiosystems (Cologne, Germany), Maxcyte, Inc.(Rockville, Md.), BTX Molecular Delivery Systems (Holliston, Mass.) andCopernicus Therapeutics Inc, (see for example U.S. Pat. No. 6,008,336).Lipofection is described in e.g., U.S. Pat. Nos. 5,049,386; 4,946,787;and 4,897,355) and lipofection reagents are sold commercially (e.g.,Transfectam™ and Lipofectin™). Cationic and neutral lipids that aresuitable for efficient receptor-recognition lipofection ofpolynucleotides include those of Feigner, WO 91/17424, WO 91/16024.

The preparation of lipid:nucleic acid complexes, including targetedliposomes such as immunolipid complexes, is well known to one of skillin the art (see, e.g., Crystal, Science 270:404-410 (1995); Blaese etal., Cancer Gene Ther. 2:291-297 (1995); Behr et al., Bioconjugate Chem.5:382-389 (1994); Remy et al., Bioconjugate Chem. 5:647-654 (1994); Gaoet al., Gene Therapy 2:710-722 (1995); Ahmad et al., Cancer Res.52:4817-4820 (1992); U.S. Pat. Nos. 4,186,183, 4,217,344, 4,235,871,4,261,975, 4,485,054, 4,501,728, 4,774,085, 4,837,028, and 4,946,787).

Additional methods of delivery include the use of packaging the nucleicacids to be delivered into EnGeneIC delivery vehicles (EDVs). These EDVsare specifically delivered to target tissues using bispecific antibodieswhere one arm of the antibody has specificity for the target tissue andthe other has specificity for the EDV. The antibody brings the EDVs tothe target cell surface and then the EDV is brought into the cell byendocytosis. Once in the cell, the contents are released (see MacDiarmidet al (2009) Nature Biotechnology 27(7):643).

The use of RNA or DNA viral based systems for the delivery of nucleicacids encoding engineered ZFPs, TALEs and/or CRISPR/Cas or TtAgo systemstake advantage of highly evolved processes for targeting a virus tospecific cells in the body and trafficking the viral payload to thenucleus. Viral vectors can be administered directly to patients (invivo) or they can be used to treat cells in vitro and the modified cellsare administered to patients (ex vivo). Conventional viral based systemsfor the delivery of ZFPs include, but are not limited to, retroviral,lentivirus, adenoviral, adeno-associated, vaccinia and herpes simplexvirus vectors for gene transfer. Integration in the host genome ispossible with the retrovirus, lentivirus, and adeno-associated virusgene transfer methods, often resulting in long term expression of theinserted transgene. Additionally, high transduction efficiencies havebeen observed in many different cell types and target tissues.

The tropism of a retrovirus can be altered by incorporating foreignenvelope proteins, expanding the potential target population of targetcells. Lentiviral vectors are retroviral vectors that are able totransduce or infect non-dividing cells and typically produce high viraltiters. Selection of a retroviral gene transfer system depends on thetarget tissue. Retroviral vectors are comprised of cis-acting longterminal repeats with packaging capacity for up to 6-10 kb of foreignsequence. The minimum cis-acting LTRs are sufficient for replication andpackaging of the vectors, which are then used to integrate thetherapeutic gene into the target cell to provide permanent transgeneexpression. Widely used retroviral vectors include those based uponmurine leukemia virus (MuLV), gibbon ape leukemia virus (GaLV), SimianImmunodeficiency virus (SIV), human immunodeficiency virus (HIV), andcombinations thereof (see, e.g., Buchscher et al., J. Virol.66:2731-2739 (1992); Johann et al., J. Virol. 66:1635-1640 (1992);Sommerfelt et al., Virol. 176:58-59 (1990); Wilson et al., J. Virol.63:2374-2378 (1989); Miller et al., J. Virol. 65:2220-2224 (1991);PCT/US94/05700).

In applications in which transient expression is preferred, adenoviralbased systems can be used. Adenoviral based vectors are capable of veryhigh transduction efficiency in many cell types and do not require celldivision. With such vectors, high titer and high levels of expressionhave been obtained. This vector can be produced in large quantities in arelatively simple system. Adeno-associated virus (“AAV”) vectors arealso used to transduce cells with target nucleic acids, e.g., in the invitro production of nucleic acids and peptides, and for in vivo and exvivo gene therapy procedures (see, e.g., West et al., Virology 160:38-47(1987); U.S. Pat. No. 4,797,368; WO 93/24641; Kotin, Human Gene Therapy5:793-801 (1994); Muzyczka, J. Clin. Invest. 94:1351 (1994).Construction of recombinant AAV vectors are described in a number ofpublications, including U.S. Pat. No. 5,173,414; Tratschin et al., Mol.Cell. Biol. 5:3251-3260 (1985); Tratschin, et al., Mol. Cell. Biol.4:2072-2081 (1984); Hermonat & Muzyczka, PNAS 81:6466-6470 (1984); andSamulski et al., J. Virol. 63:03822-3828 (1989).

At least six viral vector approaches are currently available for genetransfer in clinical trials, which utilize approaches that involvecomplementation of defective vectors by genes inserted into helper celllines to generate the transducing agent.

pLASN and MFG-S are examples of retroviral vectors that have been usedin clinical trials (Dunbar et al., Blood 85:3048-305 (1995); Kohn etal., Nat. Med. 1:1017-102 (1995); Malech et al., PNAS 94:22 12133-12138(1997)). PA317/pLASN was the first therapeutic vector used in a genetherapy trial. (Blaese et al., Science 270:475-480 (1995)). Transductionefficiencies of 50% or greater have been observed for MFG-S packagedvectors. (Ellem et al., Immunol Immunother. 44(1):10-20 (1997); Dranoffet al., Hum. Gene Ther. 1:111-2 (1997).

Recombinant adeno-associated virus vectors (rAAV) are a promisingalternative gene delivery systems based on the defective andnonpathogenic parvovirus adeno-associated type 2 virus. All vectors arederived from a plasmid that retains only the AAV 145 bp invertedterminal repeats flanking the transgene expression cassette. Efficientgene transfer and stable transgene delivery due to integration into thegenomes of the transduced cell are key features for this vector system.(Wagner et al., Lancet 351:9117 1702-3 (1998), Kearns et al., Gene Ther.9:748-55 (1996)). Other AAV serotypes, including AAV1, AAV2, AAV3, AAV4,AAV5, AAV6, AAV7, AAV8, AAV9 and AAVrh.10 and any novel AAV serotype canalso be used in accordance with the present invention. In someembodiments, mixed AAV serotypes are used (e.g. comprising ITR sequencefrom one AAV and capsid sequences from another). Examples of these mixedAAVs include AAV2/5, AAV2/6 and AAV2/8.

Replication-deficient recombinant adenoviral vectors (Ad) can beproduced at high titer and readily infect a number of different celltypes. Most adenovirus vectors are engineered such that a transgenereplaces the Ad E1a, E1b, and/or E3 genes; subsequently the replicationdefective vector is propagated in human 293 cells that supply deletedgene function in trans. Ad vectors can transduce multiple types oftissues in vivo, including nondividing, differentiated cells such asthose found in liver, kidney and muscle. Conventional Ad vectors have alarge carrying capacity. An example of the use of an Ad vector in aclinical trial involved polynucleotide therapy for antitumorimmunization with intramuscular injection (Sterman et al., Hum. GeneTher. 7:1083-9 (1998)). Additional examples of the use of adenovirusvectors for gene transfer in clinical trials include Rosenecker et al.,Infection 24:1 5-10 (1996); Sterman et al., Hum. Gene Ther. 9:71083-1089 (1998); Welsh et al., Hum. Gene Ther. 2:205-18 (1995); Alvarezet al., Hum. Gene Ther. 5:597-613 (1997); Topf et al., Gene Ther.5:507-513 (1998); Sterman et al., Hum. Gene Ther. 7:1083-1089 (1998).

Packaging cells are used to form virus particles that are capable ofinfecting a host cell. Such cells include 293 cells, which packageadenovirus, and ψ2 cells or PA317 cells, which package retrovirus. Virusparticles can also be made in insect cell systems using a baculovirus.Viral vectors used in gene therapy are usually generated by a producercell line that packages a nucleic acid vector into a viral particle. Thevectors typically contain the minimal viral sequences required forpackaging and subsequent integration into a host (if applicable), otherviral sequences being replaced by an expression cassette encoding theprotein to be expressed. The missing viral functions are supplied intrans by the packaging cell line. For example, AAV vectors used in genetherapy typically only possess inverted terminal repeat (ITR) sequencesfrom the AAV genome which are required for packaging and integrationinto the host genome. Viral DNA is packaged in a cell line, whichcontains a helper plasmid encoding the other AAV genes, namely rep andcap, but lacking ITR sequences. The cell line is also infected withadenovirus as a helper. The helper virus promotes replication of the AAVvector and expression of AAV genes from the helper plasmid. The helperplasmid is not packaged in significant amounts due to a lack of ITRsequences. Contamination with adenovirus can be reduced by, e.g., heattreatment to which adenovirus is more sensitive than AAV.

In many gene therapy applications, it is desirable that the gene therapyvector be delivered with a high degree of specificity to a particulartissue type. Accordingly, a viral vector can be modified to havespecificity for a given cell type by expressing a ligand as a fusionprotein with a viral coat protein on the outer surface of the virus. Theligand is chosen to have affinity for a receptor known to be present onthe cell type of interest. For example, Han et al., Proc. Natl. Acad.Sci. USA 92:9747-9751 (1995), reported that Moloney murine leukemiavirus can be modified to express human heregulin fused to gp70, and therecombinant virus infects certain human breast cancer cells expressinghuman epidermal growth factor receptor. This principle can be extendedto other virus-target cell pairs, in which the target cell expresses areceptor and the virus expresses a fusion protein comprising a ligandfor the cell-surface receptor. For example, filamentous phage can beengineered to display antibody fragments (e.g., FAB or Fv) havingspecific binding affinity for virtually any chosen cellular receptor.Although the above description applies primarily to viral vectors, thesame principles can be applied to nonviral vectors. Such vectors can beengineered to contain specific uptake sequences which favor uptake byspecific target cells.

Gene therapy vectors can be delivered in vivo by administration to anindividual patient, typically by systemic administration (e.g.,intravenous, intraperitoneal, intramuscular, subdermal, or intracranialinfusion) or topical application, as described below. Alternatively,vectors can be delivered to cells ex vivo, such as cells explanted froman individual patient (e.g., lymphocytes, bone marrow aspirates, tissuebiopsy) or universal donor hematopoietic stem cells, followed byreimplantation of the cells into a patient, usually after selection forcells which have incorporated the vector.

Vectors (e.g., retroviruses, adenoviruses, liposomes, etc.) containingnucleases and/or donor constructs can also be administered directly toan organism for transduction of cells in vivo. Alternatively, naked DNAcan be administered. Administration is by any of the routes normallyused for introducing a molecule into ultimate contact with blood ortissue cells including, but not limited to, injection, infusion, topicalapplication and electroporation. Suitable methods of administering suchnucleic acids are available and well known to those of skill in the art,and, although more than one route can be used to administer a particularcomposition, a particular route can often provide a more immediate andmore effective reaction than another route.

Vectors suitable for introduction of polynucleotides (e.g.nuclease-encoding and/or double-stranded donors) described hereininclude non-integrating lentivirus vectors (IDLV). See, for example, Oryet al. (1996) Proc. Natl. Acad. Sci. USA 93:11382-11388; Dull et al.(1998) J. Virol. 72:8463-8471; Zuffery et al. (1998) J. Virol.72:9873-9880; Follenzi et al. (2000) Nature Genetics 25:217-222; U.S.Pat. No. 8,936,936.

Pharmaceutically acceptable carriers are determined in part by theparticular composition being administered, as well as by the particularmethod used to administer the composition. Accordingly, there is a widevariety of suitable formulations of pharmaceutical compositionsavailable, as described below (see, e.g., Remington's PharmaceuticalSciences, 17th ed., 1989).

It will be apparent that the nuclease-encoding sequences and donorconstructs can be delivered using the same or different systems. Forexample, the nucleases and donors can be carried by the same DNA MC.Alternatively, a donor polynucleotide can be carried by a MC, while theone or more nucleases can be carried by a standard plasmid or AAVvector. Furthermore, the different vectors can be administered by thesame or different routes (intramuscular injection, tail vein injection,other intravenous injection, intraperitoneal administration and/orintramuscular injection. The vectors can be delivered simultaneously orin any sequential order.

The effective amount of nuclease(s) and donor to be administered willvary from patient to patient and according to the therapeuticpolypeptide of interest. Accordingly, effective amounts are bestdetermined by the physician administering the compositions andappropriate dosages can be determined readily by one of ordinary skillin the art. After allowing sufficient time for integration andexpression (typically 4-15 days, for example), analysis of the serum orother tissue levels of the therapeutic polypeptide and comparison to theinitial level prior to administration will determine whether the amountbeing administered is too low, within the right range or too high.Suitable regimes for initial and subsequent administrations are alsovariable, but are typified by an initial administration followed bysubsequent administrations if necessary. Subsequent administrations maybe administered at variable intervals, ranging from daily to annually toevery several years. One of skill in the art will appreciate thatappropriate immunosuppressive techniques may be recommended to avoidinhibition or blockage of transduction by immunosuppression of thedelivery vectors, see e.g., Vilquin et al., (1995) Human Gene Ther.,6:1391-1401.

Formulations for both ex vivo and in vivo administrations includesuspensions in liquid or emulsified liquids. The active ingredientsoften are mixed with excipients which are pharmaceutically acceptableand compatible with the active ingredient. Suitable excipients include,for example, water, saline, dextrose, glycerol, ethanol or the like, andcombinations thereof. In addition, the composition may contain minoramounts of auxiliary substances, such as, wetting or emulsifying agents,pH buffering agents, stabilizing agents or other reagents that enhancethe effectiveness of the pharmaceutical composition.

Applications

The methods of this invention contemplate the provision of high levelsof one or more proteins lacking in one or more LSDs in all tissues of asubject, including blood, following nuclease-mediated integration of asequence encoding the one or more proteins into an endogenous locus(e.g., albumin in liver cells or HPRT) of the subject. Thus, alsocontemplated treatment of a monogenic disease (e.g. lysosomal storagedisease). Treatment can comprise insertion of the corrected diseaseassociated gene in safe harbor locus (e.g. albumin or HPRT) forexpression of the needed enzyme and release into the blood stream.Insertion into a secretory cell, such as a liver cell for release of theproduct into the blood stream, is particularly useful and surprisinglyis shown herein to increase circulating levels of the protein in thesubject to levels by 4 to 100 fold (as compared to untreated subjects).

Thus, this technology may be of use in a condition where a patient isdeficient in some protein due to problems (e.g., problems in expressionlevel or problems with the protein expressed as sub- ornon-functioning). Particularly useful with this invention is theexpression of transgenes to correct or restore functionality inlysosomal storage disorders.

The following Examples relate to exemplary embodiments of the presentdisclosure in which the nuclease comprises a zinc finger nuclease (ZFN)or TALEN. It will be appreciated that this is for purposes ofexemplification only and that other nucleases or nuclease systems can beused, for instance homing endonucleases (meganucleases) with engineeredDNA-binding domains and/or fusions of naturally occurring of engineeredhoming endonucleases (meganucleases) DNA-binding domains andheterologous cleavage domains and/or a CRISPR/Cas or TtAgo systemsoptionally comprising an engineered single guide RNA and at least onenuclease.

EXAMPLES Example 1: Design, Construction and General Characterization ofAlbumin-Specific Nucleases

Nucleases (e.g., ZFNs, TALENs, CRISPR/Cas) targeted to albumin aredescribed in U.S. Patent Publication Nos. 20130177983; 20130177960 and20150056705). For these experiments, ZFNs comprising the ZFPs (operablylinked to the engineered cleavage domains) were used to introduce donorscomprising sequences encoding proteins lacking in LSDs to mice and areshown below in Tables 3 and 4.

TABLE 3 Mouse Albumin Designs Design SBS # F1 F2 F3 F4 F5 31523 RSDNLSEQSGNLAR DRSNLSR WRSSLRA DSSDRKK (SEQ ID (SEQ ID (SEQ ID (SEQ ID (SEQ IDNO: 3) NO: 4) NO: 5) NO: 6) NO: 7) 48641 TSGSLTR RSDALST QSATRTK LRHHLTRQAGQRRV (SEQ ID (SEQ ID (SEQ ID (SEQ ID (SEQ ID NO: 8) NO: 9) NO: 10)NO: 11) NO: 12)

TABLE 4 Target Sites of mouse albumin-specific zinc fingers SBS #Target site 31523 ttTCCTGTAACGATCGGgaactggcatc (SEQ ID NO: 13) 48641ctGAAGGTgGCAATGGTTcctctctgct (SEQ ID NO: 14)

In particular, ZFNs targeted to mouse albumin were used with AAV (e.g.,AAV2) donors in the combinations and dosages shown in FIG. 1. AAV donorsincluded homology arms to the mouse albumin locus. Donors withouthomology arms may be also be used. See, e.g., U.S. Publication Nos.20110207221. The donors encoded iduronidase (Hurler),iduronate-2-sulfatase (Hunter) or glucocerebrosidase (Gaucher) and wereexpressed from the endogenous albumin promoter.

ZFNs and donor comprising AAV were administered to the liver of thesubjects via intravenous injection through the tail vein of the animal.In each case, the ZFN pairs used were an ELD/KKR pair. AAV dose used isshown in FIG. 1 which also indicates the ratio of the AAVs comprisingthe ZFNs with the AAVs comprising the donor DNAs. FIG. 1 also shows thenumber of animals used, the group types of animals used, and the dayswhen the animals were tested. In some experiments, the animals wereadditionally subject to an immunosuppression (“+IS”) regime. In theseanimals, cyclophosphamide was administered at a dose of 50 mg/kg byintraperitoneal (IP) injection at days 0 and 14. Expression of theproteins encoded by the transgenes was evaluated using standardtechniques, namely by Western blotting in the liver and by plasmaenzymatic activity assays that measure the levels of activity of theexpressed protein in the mouse plasma.

The enzymatic assays used were fluorescence based assays performed byincubating tissue lysate or plasma with the appropriate substrateswhich, upon reaction with the active therapeutic protein, produce afluorescent product which can be measured by standard protocols. Thesubstrates used were the following: for testing the presence of activeIDUA, 4-Methylumbelliferyl alpha-L-iduronide (from Santa CruzBiotechnology) was used; for active IDS, 4-Methylumbelliferylα-L-Idopyranosiduronic Acid 2-Sulfate Disodium Salt (from Santa CruzBiotechnology) was used; for active GBA, 4-methylumbelliferylβ-D-glucopyranoside (Sigma-Aldrich). For production of a standard curve,4-methylumbelliferone (from Sigma-Aldrich) was used.

The Western blots were done using standard methods known in the art. Forthe assay of IDUA protein, an antibody purchased from R&D Systems wasused, while for the assay of the IDS protein, a different antibodypurchased from R&D Systems was used.

As shown in FIGS. 2 and 3, animals receiving both ZFN and theiduronidase donor exhibited increased expression and activity ascompared to subject not receiving donor and ZFN. Likewise, as shown inFIGS. 4 and 5, animals receiving both ZFN and the iduronate-2-sulfatasedonor exhibited increased expression and activity as compared to subjectnot receiving donor and ZFN. As shown in FIG. 6, animals receiving bothZFN and the glucocererosidase donor exhibited increased activity ascompared to subject not receiving donor and ZFN.

Thus, nuclease-mediated integration into liver of a transgene encoding aprotein lacking or deficient in an LSD significantly increases (2-100fold or more) the levels and activity of the protein in secondarytissues outside the liver, including in circulating blood.

Example 2: Selection of Cells Comprising an Integrated IDS TransgeneUsing HPRT

Nucleases (e.g., ZFNs, TALENs, CRISPR/Cas) targeted to HPRT aredescribed in U.S. Pat. No. 8,895,264 and U.S. Patent Publication No.20130137104. For these experiments, ZFNs comprising the ZFPs (operablylinked to the engineered cleavage domains) were used to introduce donorscomprising sequences encoding proteins lacking in LSDs to the HPRT locusin K562 cells and human CD34+ HSC. Specifically, the nuclease pairlisted below in Tables 5 and 6 was used to introduce the IDS transgene.

TABLE 5 human HPRT designs Target species/ SBS # F1 F2 F3 F4 F5 F6 HumanTSGSLSR QSGNLAR QSSDLSR RSDHLSQ DNSNRIN NA 34306 (SEQ ID (SEQ ID (SEQ ID(SEQ ID (SEQ ID NO: 15) NO: 4) NO: 16) NO: 17) NO: 18) Human QSGDLTRTSGSLTR RSDVLSE RNQHRKT RSAHLSR DRSDLSR 34303 (SEQ ID (SEQ ID (SEQ ID(SEQ ID (SEQ ID (SEQ ID NO: 19) NO: 8) NO: 20) NO: 21) NO: 22) NO: 23)

TABLE 6 Target Sites of human HPRT-specific zinc fingers SBS #Target site 34306 tgCACAGGgGCTGAAGTTgtcccacagg (SEQ ID NO: 24) 34303tgGCCAGGAGGCTGGTTGCAaacatttt (SEQ ID NO: 25)

For these experiments, the IDS cDNA donor was delivered via an AAV2/6particle, and the IDS cDNA transgene comprised homology arms for theHPRT regions flanking the cut site (see FIG. 7). The homology arms wereapproximately and the IDS encoding transgene was approximately 1652 basepairs.

To integrate the IDS cDNA transgene and assay its expression, HPRTspecific zinc finger nucleases in the form of mRNA were transfected intohuman peripheral blood mobilized hematopoietic stem cells (CD34+ cells,from a male donor, i.e. these cells only had one copy of the HPRT geneper cell) or K562 cells. Briefly, 200,000 cells were transfected by BTXnucleofection by standard methods. The concentrations of nucleases were40 μg/mL mRNA each per nucleofection. An AAV6 transgene donor wasdelivered 16 hours prior to transfection at an MOI of 1e4 viralgenomes/cell. 24 hours after transfection the cells were then culturedin erythroid differentiation medium (EDM) on the basis of IMDMsupplemented with stabilized glutamine, 330 μg/mL holo-humantransferrin, 10 μg/mL recombinant human insulin, 2 IU/mL heparin, and 5%human plasma. The expansion procedure comprised 3 steps. In the firststep (day 0 to day 7), 10⁴ cells/mL CD34+ cells were cultured in EDM inthe presence of 10 μM hydrocortisone, 100 ng/mL SCF, 5 ng/mL IL-3, and 3IU/mL Epo. On day 4, 1 volume of cell culture was diluted in 4 volumesof fresh medium containing SCF, IL-3, Epo, and hydrocortisone. 100 nM6-TG was added to wells at this stage. In the second step (day 7 to day11), the cells were resuspended at 10⁵ cells/mL in EDM supplemented withSCF and Epo. In the third step (day 11 to day 18), the cells werecultured in EDM supplemented with Epo alone. At day 11, 6-TGconcentration was increased to 300 nM. Cell counts were adjusted to7.5×10⁵ to 1×10⁶ and 5-10×10⁶ cells/mL on days 11 and 15, respectively.On day 13, 6-TG concentration was increased to 2 μM. Cells wereharvested for protein lysate and genomic DNA at day 18 (19 days posttransfection). Supernatant was also collected for IDS enzymatic activityanalysis. Integration of the exogenous DNA sequence into HPRT wasassayed by high-throughput sequencing (Miseq, Illumina). IDS enzymaticactivity was conducted by incubating cell lysate and supernatant with4-Methylumbelliferyl α-L-Iduronate-2-Sulfate as described above for 4hours at 37° C., then adding recombinant IDUA to cleave the substrate.Fluorescence was then measured at 450 nm emission after 365 nmexcitation. Viability was measured with propidium iodide via flowcytometry. As a control, cells were also transfected with GFP encodingdonors.

For the experiments done in K562 cells, viability of cells modified witha full IDS cDNA transgene downstream of a splice acceptor (SA) and 2Aself-cleaving peptide sequence were assayed by flow cytometry with andwithout 6-TG selection (see FIG. 8A). The percent NHEJ (FIG. 8B)following nuclease cleavage was stable in cells grown without 6-TGselection, while cells modified with the ZFNs and the therapeutic IDStransgene donor showed decreased levels of NHEJ after 6-TG selection asassayed by MiSeq analysis (Illumina), done according to methods known inthe art. Sequencing analysis also demonstrated that the levels oftargeted integration of the IDS transgene reached 90% of all allelesafter 6-TG selection (FIG. 8C). A 3-fold increase in IDS enzymaticactivity in cell culture supernatant in the cells transfected with theIDS transgene was observed after two weeks of 6-TG selection (FIG. 8D, *P<0.05 compared to unselected controls).

These experiments were also done in human mPB CD34+ cells. Viability andpercent NHEJ were measured as described above (see FIGS. 9A and 9B) incells undergoing erythroid differentiation. Relatively stable NHEJ indifferentiating CD34+ cells modified with ZFNs without 6-TG selectionwas observed, while cells modified with ZFNs and therapeutic IDStransgene donor showed decreased levels of NHEJ after 6-TG selection asassayed by Miseq analysis. Levels of TI reach 96% of all alleles after6-TG selection as assayed by sequence analysis in cells treated with thenuclease pair and the IDS transgene donor (FIG. 9C), and a 3-foldincrease in IDS enzymatic activity in cell culture supernatant after oneweek of 6-TG selection, and an 8-fold increase in enzymatic activity incell lysate after 2 weeks selection was observed (FIG. 9D, * P<0.05compared to unselected controls).

Example 3: Detection of LSD Donor Transgenes In Vivo

A. Albumin

Donors for four lysosomal storage disease transgenes were constructedfor the purpose of integrating into the mouse albumin gene in intron1:the transgenes were α-galactosidase A (GLA), Acid β-glucosidase (GBA),α-L-iduronidase (IDUA) and Iduronate-2-sulfatase (IDS), genes lacking inFabry's, Gaucher's, Hurler's and Hunter's diseases, respectively.

The donors were then used in in vivo studies to observe integration ofthe transgenes into albumin. The murine albumin specific ZFNs and thedonors were inserted all into AAV2/8 virus, and then were injected intomice. In these experiments, the virus was formulated for injection inD-PBS+35 mM NaCl, 5% glycerol and frozen prior to injection. The donor-and nuclease-containing viruses were mixed together prior to freezing.At Day 0, the virus preparation was thawed and administered to the miceby tail vein injection where the total injection volume was 200 μL. Atthe indicated times, the mice were sacrificed and then serum, liver andspleen were harvested for protein and DNA analysis by standardprotocols. The dose groups are shown below in Table 7.

TABLE 7 Treatment groups for LSD transgene integration N/group/ GroupTreatment time point 1 murine Alb intron 1+ Fabry @ 1:5 ratio; ZFN 3 @3.0e11, Donor @ 1.5e12 2 murine Alb intron 1+ Hunters donor @ 1:5 ratio;3 ZFN @ 3.0e11, Donor @ 1.5e12 3 murine Alb intron 1+ Hurlers donor @1:5 ratio; 3 ZFN @ 3.0e11, Donor @ 1.5e12 4 murine Alb intron 1 3 5Fabry donor only 2 6 Hunter's donor only 2 7 Hurler's donor only 2

At day 30, liver homogenates were analyzed by Western blot analysis forthe presence of the LSD proteins encoded by the donors. Liverhomogenates were analyzed by Western blot using standard methodologies,using the following primary antibodies: α-Galactosidase A(Fabry's)-specific rabbit monoclonal antibody was purchased from SinoBiological, Inc.; Human α-L-Iduronidase (Hurler's)-specific mousemonoclonal antibody was purchased from R&D Systems; Human iduronate2-Sulfatase (Hunter's)-specific mouse monoclonal was purchased from R&DSystems. The results showed expression, especially in the mice thatreceived both the ZFN containing virus and the transgene donorcontaining virus.

The manner of integration of the donor DNA into the albumin locus wasalso investigated. In all of the transgene integrations, integration viaboth HRD and NHEJ mechanisms was observed.

Donor DNAs were also designed to include a tag sequence for laterrecognition of the protein using the tag specific antibodies. The donorswere integrated as described above, and all were capable of integrationas demonstrated by PCR.

B. HPRT

Donors as described herein are integrated into the mouse HPRT gene asdescribed above in Example 3, part A for albumin. An exemplary treatmentschedule for donors comprising one or more proteins lacking or deficientin an LSD is shown in Table 8:

TABLE 8 Treatment groups for LSD transgene integration N/group/ GroupTreatment time point 1 murine HPRT intron 1+ donor (IDS, IDUA, α- 3Galactosidase A, alpha-glucosidase, etc.) @ 1:5 ratio; ZFN @ 3.0e11,Donor @ 1.5e12 2 murine HPRT intron 1 3 3 Donor only 3 (per donor)

At day 30, liver homogenates are analyzed by Western blot analysis forthe presence of the protein encoded by the donor. Liver homogenates areanalyzed by Western blot using standard methodologies, using theappropriate specific mouse monoclonal purchased from R&D Systems. Theresults show high IDS expression in the animals that receive both theZFN and the IDS donor.

Example 4: Detection of hIDUA in MPS I Mice

We next sought to see if expression of human IDUA would be detectable inMPS I (Idua −/−) mice or MPS II (Ids Y/−). Idua −/− mice (see Hartung etal (2004) Mol Ther 9(6):866) and Ids Y/− mice (see e.g. Cardone et al(2006) Hum Mol Genet 15(7):1225) were treated as described above inExample 3 for the wild type mice using albumin targeted ZFNs. Human IDUAand human IDS were assayed as described above in several tissues in theanimals, and the hIDUA was detected for at least 60 days post treatment(FIG. 10), while the hIDS was detectable for at least 84 days in theplasma (FIG. 11). Further, levels of GAG accumulation was measured inthe urine and tissues of the animals as described previously (Hartungibid).

The results (FIG. 12 and FIG. 13) demonstrated that the AAV mediateddelivery of ZFNs and the hIDUA transgene donor reduced GAG levels.

Example 5: Correction of Abnormal Neurologic Function in MPS I Mice

MPS I mice are evaluated for spatial memory and navigation using aBarnes Maze (see e.g. Sunyer et al (2007) Protocol Exchangedoi:10.1038/nprot.2007.390). In brief, the maze has 20-40 holes aroundthe periphery, where one hole leads to an escape box. Visual cues areplaced on the walls of the maze and the mouse is trained to find thehole leading to the escape box. The basic function of Barnes maze is tomeasure the ability of a mouse to learn and remember the location of atarget zone using a configuration of distal visual cues located aroundthe testing area. After mastering the maze, the target hole is blockedoff and the mouse is placed in the maze and its search strategies areanalyzed to see how it searches for the hole to the escape box. Thesearch strategies are defined as either 1) Direct (spatial) where themouse moves directly or nearly directly to the hole, 2) Mixed, where thehole searches are separated by crossing through the center of the maze,or the mouse conducts an unorganized search, and 3) Serial, where themouse finds the target hole by visiting the neighbor holes in either theclockwise or counterclockwise holes in a serial manner.

The MPS I mice treated with the albumin ZFNs and AAV-hIDUA donor areable to find the target hole faster and in a more organized manner thanthe control MPS1 mice.

All patents, patent applications and publications mentioned herein arehereby incorporated by reference in their entirety.

Although disclosure has been provided in some detail by way ofillustration and example for the purposes of clarity of understanding,it will be apparent to those skilled in the art that various changes andmodifications can be practiced without departing from the spirit orscope of the disclosure. Accordingly, the foregoing descriptions andexamples should not be construed as limiting.

What is claimed is:
 1. A method of treating a mouse or human withmucopolysaccharidosis type I (MPS I) or mucopolysaccharidosis type II(MPS II) disease, the method comprising intravenously injecting firstand second AAV vectors, encoding first and second ZFNs of a pair of zincfinger nucleases that cleave in an endogenous albumin gene, into themouse or human with MPS I or MPS II disease; intravenously injecting athird AAV vector comprising a transgene encoding (a) an iduronidase(IDUA) protein into the mouse or human with MPS I disease or (b) a DNAsequence encoding an iduronate sulfatase (IDS) protein into the mouse orhuman with MPS II disease, wherein the transgene is flanked by sequenceshaving homology with the endogenous albumin gene; wherein the first,second and third AAV vectors are delivered at a ratio of 1:1:8 andfurther wherein the transgene is integrated into the endogenous albumingene in liver cells of the mouse or human and the liver cells expressand secrete therapeutic amounts of the IDUA or IDS protein and a symptomof the MPS I or MPS II disease is treated in the mouse or human.
 2. Themethod of claim 1, wherein the method treats neurological deficitsassociated with MPS I or MPS II disease.
 3. The method of claim 1,wherein the method reduces GAG accumulation in the mouse or human. 4.The method of claim 1, wherein the AAV vectors are AAV2 and/or AAV6vectors.